diff --git a/CDP4Common.NetCore.Tests/Validation/DtoValueValidatorTestFixture.cs b/CDP4Common.NetCore.Tests/Validation/DtoValueValidatorTestFixture.cs
index 0da82949..60f51133 100644
--- a/CDP4Common.NetCore.Tests/Validation/DtoValueValidatorTestFixture.cs
+++ b/CDP4Common.NetCore.Tests/Validation/DtoValueValidatorTestFixture.cs
@@ -84,8 +84,8 @@ public void Setup()
                 NumberSet = NumberSetKind.NATURAL_NUMBER_SET
             };
 
-            this.valueDefinitions =
-            [
+            this.valueDefinitions = new List<EnumerationValueDefinition>()
+            {
                 new EnumerationValueDefinition(Guid.NewGuid(), 1)
                 {
                     Name = "LOW",
@@ -97,19 +97,46 @@ public void Setup()
                     Name = "MEDIUM",
                     ShortName = "medium"
                 }
-            ];
+            };
 
             this.enumerationParameterType.ValueDefinition.Add(new OrderedItem { V = this.valueDefinitions[0].Iid });
             this.enumerationParameterType.ValueDefinition.Add(new OrderedItem { V = this.valueDefinitions[1].Iid });
 
             this.valueSet = new ParameterValueSet(Guid.NewGuid(), 1)
             {
-                Reference = new ValueArray<string>([ObjectValueValidator.DefaultValue]),
-                Computed = new ValueArray<string>([ObjectValueValidator.DefaultValue]),
-                Manual = new ValueArray<string>([ObjectValueValidator.DefaultValue])
+                Reference = new ValueArray<string>(new List<string>() { ObjectValueValidator.DefaultValue }),
+                Computed = new ValueArray<string>(new List<string>() { ObjectValueValidator.DefaultValue }),
+                Manual = new ValueArray<string>(new List<string>() { ObjectValueValidator.DefaultValue }),
+                Formula = new ValueArray<string>(new List<string>() { ObjectValueValidator.DefaultValue })
             };
         }
 
+        [Test]
+        public void VerifyQuantityFormula()
+        {
+            var parameter = new Parameter(Guid.NewGuid(), 1)
+            {
+                ParameterType = this.simpleQuantityKind.Iid,
+                Scale = this.ratioScale.Iid
+            };
+
+            var classlessDto = new ClasslessDTO()
+            {
+                {"Manual", new ValueArray<string>(new List<string>(){"1"})},
+                {"Computed", new ValueArray<string>(new List<string>(){"2"})},
+                {"Reference", new ValueArray<string>(new List<string>(){"3"})},
+                {"Formula", new ValueArray<string>(new List<string>(){"=CELLNAME"})},
+            };
+
+            var things = new List<Thing>();
+            things.Add(this.simpleQuantityKind);
+            things.Add(this.ratioScale);
+
+            var result = parameter.ValidateAndCleanup(classlessDto, things);
+
+            Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
+        }
+
         [Test]
         public void VerifyBooleanParameterTypeValidationAndCleanup()
         {
@@ -526,7 +553,7 @@ public void VerifyQuantityKindWithNaturalValidationAndCleanup()
             });
 
             result = this.simpleQuantityKind.Validate(1.00, this.ratioScale.Iid, out cleanedValue, things);
-            
+
             Assert.Multiple(() =>
             {
                 Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
@@ -583,14 +610,14 @@ public void VerifyQuantityKindWithIntegerValidationAndCleanup()
             });
 
             result = this.simpleQuantityKind.Validate(1.00, this.ratioScale.Iid, out cleanedValue, things);
-            
+
             Assert.Multiple(() =>
             {
                 Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
                 Assert.That(cleanedValue, Is.EqualTo("1"));
             });
 
-            result = this.simpleQuantityKind.Validate(1.001, this.ratioScale.Iid, out _, things); 
+            result = this.simpleQuantityKind.Validate(1.001, this.ratioScale.Iid, out _, things);
 
             Assert.Multiple(() =>
             {
@@ -627,10 +654,10 @@ public void VerifyQuantityKindWithRealValidationAndCleanup()
 
             this.valueSet.Manual[0] = "-1";
 
-            result = this.simpleQuantityKind.ValidateAndCleanup(this.valueSet,  this.ratioScale.Iid, things);
+            result = this.simpleQuantityKind.ValidateAndCleanup(this.valueSet, this.ratioScale.Iid, things);
             Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
 
-            result = this.simpleQuantityKind.Validate(1,  this.ratioScale.Iid, out var cleanedValue, things);
+            result = this.simpleQuantityKind.Validate(1, this.ratioScale.Iid, out var cleanedValue, things);
 
             Assert.Multiple(() =>
             {
@@ -639,7 +666,7 @@ public void VerifyQuantityKindWithRealValidationAndCleanup()
             });
 
             result = this.simpleQuantityKind.Validate(1.00, this.ratioScale.Iid, out cleanedValue, things);
-            
+
             Assert.Multiple(() =>
             {
                 Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
@@ -653,7 +680,7 @@ public void VerifyQuantityKindWithRealValidationAndCleanup()
                 Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
                 Assert.That(cleanedValue, Is.EqualTo("1.001"));
             });
-            
+
             result = this.simpleQuantityKind.Validate(false, this.ratioScale.Iid, out _, things);
 
             Assert.Multiple(() =>
@@ -673,7 +700,7 @@ public void VerifyQuantityKindWithRationalValidationAndCleanup()
                 this.ratioScale
             };
 
-            var result = this.simpleQuantityKind.Validate(false,  this.ratioScale.Iid, out _, things);
+            var result = this.simpleQuantityKind.Validate(false, this.ratioScale.Iid, out _, things);
 
             Assert.Multiple(() =>
             {
@@ -711,8 +738,8 @@ public void VerifySampledFunctionParameterTypeValidationAndCleanup()
                 MeasurementScale = this.ratioScale.Iid
             };
 
-            sampledFunctionParameterType.IndependentParameterType.Add(new OrderedItem(){V = independentParameterAssignment.Iid});
-            sampledFunctionParameterType.DependentParameterType.Add(new OrderedItem(){V = dependentParameterAssignment.Iid});
+            sampledFunctionParameterType.IndependentParameterType.Add(new OrderedItem() { V = independentParameterAssignment.Iid });
+            sampledFunctionParameterType.DependentParameterType.Add(new OrderedItem() { V = dependentParameterAssignment.Iid });
 
             Assert.Multiple(() =>
             {
@@ -730,7 +757,7 @@ public void VerifySampledFunctionParameterTypeValidationAndCleanup()
                 Assert.That(() => sampledFunctionParameterType.ValidateAndCleanup(this.valueSet.Manual, "Manual", things), Throws.Exception.TypeOf<ThingNotFoundException>()
                     .With.Message.Contain("The provided collection of referenced Things does not contain the IndependentParameterTypeAssignment"));
             });
-            
+
             things.Add(independentParameterAssignment);
 
             Assert.Multiple(() =>
@@ -752,7 +779,7 @@ public void VerifySampledFunctionParameterTypeValidationAndCleanup()
                 Assert.That(() => sampledFunctionParameterType.ValidateAndCleanup(this.valueSet.Manual, "Manual", things), Throws.Exception.TypeOf<ThingNotFoundException>()
                     .With.Message.Contain("The provided collection of referenced Things does not contain the DependentParameterTypeAssignment"));
             });
-            
+
             things.Add(dependentParameterAssignment);
 
             Assert.Multiple(() =>
@@ -775,18 +802,18 @@ public void VerifySampledFunctionParameterTypeValidationAndCleanup()
                     .With.Message.Contain("The ValueArray Manual ({\"-\"}) does not have the required amount of values !"));
             });
 
-            this.valueSet.Manual = new ValueArray<string>(["-","-"]);
-            this.valueSet.Computed = new ValueArray<string>(["-","-","-","-"]);
-            this.valueSet.Reference = new ValueArray<string>(["-","-", "-","-", "-","-"]);
+            this.valueSet.Manual = new ValueArray<string>(new List<string>() { "-", "-" });
+            this.valueSet.Computed = new ValueArray<string>(new List<string>() { "-", "-", "-", "-" });
+            this.valueSet.Reference = new ValueArray<string>(new List<string>() { "-", "-", "-", "-", "-", "-" });
 
             var result = sampledFunctionParameterType.ValidateAndCleanup(this.valueSet, things);
 
             Assert.Multiple(() =>
             {
                 Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
-                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(["-","-"])));
-                Assert.That(this.valueSet.Computed, Is.EquivalentTo(new ValueArray<string>(["-","-","-","-"])));
-                Assert.That(this.valueSet.Reference, Is.EquivalentTo(new ValueArray<string>(["-","-","-","-","-","-"])));
+                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(new List<string>() { "-", "-" })));
+                Assert.That(this.valueSet.Computed, Is.EquivalentTo(new ValueArray<string>(new List<string>() { "-", "-", "-", "-" })));
+                Assert.That(this.valueSet.Reference, Is.EquivalentTo(new ValueArray<string>(new List<string>() { "-", "-", "-", "-", "-", "-" })));
             });
 
             result = sampledFunctionParameterType.ValidateAndCleanup(this.valueSet.Manual, "Manual", things);
@@ -794,7 +821,7 @@ public void VerifySampledFunctionParameterTypeValidationAndCleanup()
             Assert.Multiple(() =>
             {
                 Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
-                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(["-","-"])));
+                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(new List<string>() { "-", "-" })));
             });
 
             this.valueSet.Manual[0] = "1";
@@ -816,7 +843,7 @@ public void VerifySampledFunctionParameterTypeValidationAndCleanup()
             Assert.Multiple(() =>
             {
                 Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
-                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(["true","2"])));
+                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(new List<string>() { "true", "2" })));
             });
 
             this.valueSet.Manual[0] = "1";
@@ -826,7 +853,7 @@ public void VerifySampledFunctionParameterTypeValidationAndCleanup()
             Assert.Multiple(() =>
             {
                 Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
-                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(["true","2"])));
+                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(new List<string>() { "true", "2" })));
             });
 
             this.valueSet.Manual[1] = "-1";
@@ -852,8 +879,8 @@ public void VerifyCompoundParameterTypeValidationAndCleanup()
                 ParameterType = this.textParameterType.Iid
             };
 
-            compoundParameterType.Component.Add(new OrderedItem(){V = boolParameterTypeComponent.Iid});
-            compoundParameterType.Component.Add(new OrderedItem(){V = textParameterTypeComponent.Iid});
+            compoundParameterType.Component.Add(new OrderedItem() { V = boolParameterTypeComponent.Iid });
+            compoundParameterType.Component.Add(new OrderedItem() { V = textParameterTypeComponent.Iid });
 
             Assert.Multiple(() =>
             {
@@ -871,7 +898,7 @@ public void VerifyCompoundParameterTypeValidationAndCleanup()
                 Assert.That(() => compoundParameterType.ValidateAndCleanup(this.valueSet.Manual, "Manual", things), Throws.Exception.TypeOf<ThingNotFoundException>()
                     .With.Message.Contain("The provided collection of referenced Things does not contain the ParameterTypeComponent"));
             });
-            
+
             things.Add(boolParameterTypeComponent);
 
             Assert.Multiple(() =>
@@ -879,7 +906,7 @@ public void VerifyCompoundParameterTypeValidationAndCleanup()
                 Assert.That(() => compoundParameterType.ValidateAndCleanup(this.valueSet, things), Throws.Exception.TypeOf<ThingNotFoundException>()
                     .With.Message.Contain("The provided collection of Things does not contain a reference to the ParameterType"));
 
-                Assert.That(() => compoundParameterType.ValidateAndCleanup(this.valueSet.Manual,"Manual", things), Throws.Exception.TypeOf<ThingNotFoundException>()
+                Assert.That(() => compoundParameterType.ValidateAndCleanup(this.valueSet.Manual, "Manual", things), Throws.Exception.TypeOf<ThingNotFoundException>()
                     .With.Message.Contain("The provided collection of Things does not contain a reference to the ParameterType"));
             });
 
@@ -893,7 +920,7 @@ public void VerifyCompoundParameterTypeValidationAndCleanup()
                 Assert.That(() => compoundParameterType.ValidateAndCleanup(this.valueSet.Manual, "Manual", things), Throws.Exception.TypeOf<ThingNotFoundException>()
                     .With.Message.Contain("The provided collection of referenced Things does not contain the ParameterTypeComponent"));
             });
-            
+
             things.Add(textParameterTypeComponent);
 
             Assert.Multiple(() =>
@@ -916,18 +943,18 @@ public void VerifyCompoundParameterTypeValidationAndCleanup()
                     .With.Message.Contain("The ValueArray Manual ({\"-\"}) does not have the required amount of values ! Expected: 2 Received: 1"));
             });
 
-            this.valueSet.Manual = new ValueArray<string>(["-","-"]);
-            this.valueSet.Computed = new ValueArray<string>(["-","-"]);
-            this.valueSet.Reference = new ValueArray<string>(["-","-"]);
+            this.valueSet.Manual = new ValueArray<string>(new List<string>() { "-", "-" });
+            this.valueSet.Computed = new ValueArray<string>(new List<string>() { "-", "-" });
+            this.valueSet.Reference = new ValueArray<string>(new List<string>() { "-", "-" });
 
             var result = compoundParameterType.ValidateAndCleanup(this.valueSet, things);
 
             Assert.Multiple(() =>
             {
                 Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
-                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(["-","-"])));
-                Assert.That(this.valueSet.Computed, Is.EquivalentTo(new ValueArray<string>(["-","-"])));
-                Assert.That(this.valueSet.Reference, Is.EquivalentTo(new ValueArray<string>(["-","-"])));
+                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(new List<string>() { "-", "-" })));
+                Assert.That(this.valueSet.Computed, Is.EquivalentTo(new ValueArray<string>(new List<string>() { "-", "-" })));
+                Assert.That(this.valueSet.Reference, Is.EquivalentTo(new ValueArray<string>(new List<string>() { "-", "-" })));
             });
 
             result = compoundParameterType.ValidateAndCleanup(this.valueSet.Manual, "Manual", things);
@@ -935,7 +962,7 @@ public void VerifyCompoundParameterTypeValidationAndCleanup()
             Assert.Multiple(() =>
             {
                 Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
-                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(["-","-"])));
+                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(new List<string>() { "-", "-" })));
             });
 
             this.valueSet.Manual[0] = "1";
@@ -946,7 +973,7 @@ public void VerifyCompoundParameterTypeValidationAndCleanup()
             Assert.Multiple(() =>
             {
                 Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
-                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(["true","2"])));
+                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(new List<string>() { "true", "2" })));
             });
 
             this.valueSet.Manual[0] = "1";
@@ -957,7 +984,7 @@ public void VerifyCompoundParameterTypeValidationAndCleanup()
             Assert.Multiple(() =>
             {
                 Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
-                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(["true","2"])));
+                Assert.That(this.valueSet.Manual, Is.EquivalentTo(new ValueArray<string>(new List<string>() { "true", "2" })));
             });
 
             this.valueSet.Manual[1] = " ";
@@ -986,7 +1013,7 @@ public void VerifyParameterValidation()
 
             var things = new List<Thing>();
 
-            Assert.That(() => parameter.ValidateAndCleanup(classlessDto,things), Throws.Exception.TypeOf<ThingNotFoundException>()
+            Assert.That(() => parameter.ValidateAndCleanup(classlessDto, things), Throws.Exception.TypeOf<ThingNotFoundException>()
                 .With.Message.Contain("The provided collection of Things does not contain a reference to the ParameterType"));
 
             things.Add(this.booleanParameterType);
@@ -997,12 +1024,12 @@ public void VerifyParameterValidation()
 
             ((ValueArray<string>)classlessDto["Manual"])[0] = "FALSE";
 
-            result =  parameter.ValidateAndCleanup(classlessDto, things);
+            result = parameter.ValidateAndCleanup(classlessDto, things);
 
             Assert.Multiple(() =>
             {
                 Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
-                Assert.That( ((ValueArray<string>)classlessDto["Manual"])[0], Is.EqualTo("false"));
+                Assert.That(((ValueArray<string>)classlessDto["Manual"])[0], Is.EqualTo("false"));
             });
 
             ((ValueArray<string>)classlessDto["Manual"])[0] = "2";
diff --git a/CDP4Common.Tests/Validation/DtoValueValidatorTestFixture.cs b/CDP4Common.Tests/Validation/DtoValueValidatorTestFixture.cs
index 35dfb1c3..c654f702 100644
--- a/CDP4Common.Tests/Validation/DtoValueValidatorTestFixture.cs
+++ b/CDP4Common.Tests/Validation/DtoValueValidatorTestFixture.cs
@@ -106,10 +106,37 @@ public void Setup()
             {
                 Reference = new ValueArray<string>(new List<string>(){ObjectValueValidator.DefaultValue}),
                 Computed = new ValueArray<string>(new List<string>(){ObjectValueValidator.DefaultValue}),
-                Manual = new ValueArray<string>(new List<string>(){ObjectValueValidator.DefaultValue})
+                Manual = new ValueArray<string>(new List<string>(){ObjectValueValidator.DefaultValue}),
+                Formula = new ValueArray<string>(new List<string>() { ObjectValueValidator.DefaultValue })
             };
         }
 
+        [Test]
+        public void VerifyQuantityFormula()
+        {
+            var parameter = new Parameter(Guid.NewGuid(), 1)
+            {
+                ParameterType = this.simpleQuantityKind.Iid,
+                Scale = this.ratioScale.Iid
+            };
+
+            var classlessDto = new ClasslessDTO()
+            {
+                {"Manual", new ValueArray<string>(new List<string>(){"1"})},
+                {"Computed", new ValueArray<string>(new List<string>(){"2"})},
+                {"Reference", new ValueArray<string>(new List<string>(){"3"})},
+                {"Formula", new ValueArray<string>(new List<string>(){"=CELLNAME"})},
+            };
+
+            var things = new List<Thing>();
+            things.Add(this.simpleQuantityKind);
+            things.Add(this.ratioScale);
+
+            var result = parameter.ValidateAndCleanup(classlessDto, things);
+
+            Assert.That(result.ResultKind, Is.EqualTo(ValidationResultKind.Valid));
+        }
+
         [Test]
         public void VerifyBooleanParameterTypeValidationAndCleanup()
         {
diff --git a/CDP4Common/CDP4Common.csproj b/CDP4Common/CDP4Common.csproj
index 6a9d5be4..76c6c108 100644
--- a/CDP4Common/CDP4Common.csproj
+++ b/CDP4Common/CDP4Common.csproj
@@ -4,7 +4,7 @@
     <TargetFrameworks>net48;netstandard2.0</TargetFrameworks>
     <Company>Starion Group S.A.</Company>
     <Title>CDP4Common Community Edition</Title>
-    <VersionPrefix>27.2.0</VersionPrefix>
+    <VersionPrefix>27.2.1</VersionPrefix>
     <Description>CDP4 Common Class Library that contains DTOs, POCOs</Description>
     <Copyright>Copyright © Starion Group S.A.</Copyright>
     <Authors>Sam, Merlin, Alex, Naron, Alexander, Yevhen, Nathanael, Ahmed</Authors>
diff --git a/CDP4Common/Validation/DtoValueValidator.cs b/CDP4Common/Validation/DtoValueValidator.cs
index 5ec7b692..f77c1a8e 100644
--- a/CDP4Common/Validation/DtoValueValidator.cs
+++ b/CDP4Common/Validation/DtoValueValidator.cs
@@ -404,9 +404,9 @@ public static ValidationResult ValidateAndCleanup(this Parameter parameter, Clas
 
             foreach (var kvp in classlessDto)
             {
-                if (!(kvp.Value is ValueArray<string> valueArray))
+                if (!(kvp.Value is ValueArray<string> valueArray) || kvp.Key == nameof(ParameterValueSet.Formula))
                 {
-                    continue;
+                        continue;
                 }
 
                 var validationResult = parameterType.ValidateAndCleanup(valueArray, kvp.Key, parameter.Scale, things, provider);
@@ -448,7 +448,7 @@ public static ValidationResult ValidateAndCleanup(this ParameterOverride paramet
 
             foreach (var kvp in classlessDto)
             {
-                if (!(kvp.Value is ValueArray<string> valueArray))
+                if (!(kvp.Value is ValueArray<string> valueArray) || kvp.Key == nameof(ParameterValueSet.Formula))
                 {
                     continue;
                 }
diff --git a/CDP4Dal/CDP4Dal.csproj b/CDP4Dal/CDP4Dal.csproj
index 850e04d1..2d6894b3 100644
--- a/CDP4Dal/CDP4Dal.csproj
+++ b/CDP4Dal/CDP4Dal.csproj
@@ -4,7 +4,7 @@
     <TargetFrameworks>net48;netstandard2.0</TargetFrameworks>
     <Company>Starion Group S.A.</Company>
     <Title>CDP4Dal Community Edition</Title>
-    <VersionPrefix>27.2.0</VersionPrefix>
+    <VersionPrefix>27.2.1</VersionPrefix>
     <Description>CDP4 Data Access Layer library, a consumer of an ECSS-E-TM-10-25 Annex C API</Description>
     <Copyright>Copyright © Starion Group S.A.</Copyright>
     <Authors>Sam, Merlin, Alex, Naron, Alexander, Yevhen, Nathanael, Ahmed</Authors>
diff --git a/CDP4Dal/Session.cs b/CDP4Dal/Session.cs
index b190e59c..d7fec261 100644
--- a/CDP4Dal/Session.cs
+++ b/CDP4Dal/Session.cs
@@ -396,10 +396,15 @@ public async Task Open(bool activeMessageBus = true)
                 // clear cache
                 await this.Assembler.Clear();
 
+                this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.EndUpdate));
+
                 throw new IncompleteModelException("The Person object that matches the user specified in the Credentials could not be found");
             }
+            else
+            {
+                this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.EndUpdate));
+            }
 
-            this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.EndUpdate));
 
             logger.Info("Synchronization with the {0} server done in {1} [ms]", this.DataSourceUri, sw.ElapsedMilliseconds);
 
@@ -493,11 +498,17 @@ public async Task Read(Iteration iteration, DomainOfExpertise domain, bool activ
 
             this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.BeginUpdate));
 
-            await this.Assembler.Synchronize(enumerable, activeMessageBus);
+            try
+            {
+                await this.Assembler.Synchronize(enumerable, activeMessageBus);
 
-            this.AddIterationToOpenList(iteration.Iid, domain);
+                this.AddIterationToOpenList(iteration.Iid, domain);
+            }
+            finally
+            {
+                this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.EndUpdate));
+            }
 
-            this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.EndUpdate));
             logger.Info("Synchronization with the {0} server done", this.DataSourceUri);
         }
 
@@ -838,8 +849,16 @@ private async Task AfterReadOrWriteOrUpdate(IList<CDP4Common.DTO.Thing> things,
             var sw = new Stopwatch();
             logger.Info($"Synchronization of DTOs for {caller} from/to server {0} started", this.DataSourceUri);
             this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.BeginUpdate));
-            await this.Assembler.Synchronize(things);
-            this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.EndUpdate));
+
+            try
+            {
+                await this.Assembler.Synchronize(things);
+            }
+            finally
+            {
+                this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.EndUpdate));
+            }
+
             logger.Info($"Synchronization of DTOs for {caller} from/to server {0} done in {1} [ms]", this.DataSourceUri, sw.ElapsedMilliseconds);
         }
 
@@ -1087,8 +1106,15 @@ public async Task CloseRdl(SiteReferenceDataLibrary sRdl)
             }
 
             this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.BeginUpdate));
-            await Task.WhenAll(tasks);
-            this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.EndUpdate));
+
+            try
+            {
+                await Task.WhenAll(tasks);
+            }
+            finally
+            {
+                this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.EndUpdate));
+            }
 
             foreach (var siteReferenceDataLibrary in orderedRdlsToClose)
             {
@@ -1155,8 +1181,16 @@ private async Task Update(Thing thing, bool isRefresh = true)
         public async Task CloseModelRdl(ModelReferenceDataLibrary modelRdl)
         {
             this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.BeginUpdate));
-            await this.Assembler.CloseRdl(modelRdl);
-            this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.EndUpdate));
+
+            try
+            {
+                await this.Assembler.CloseRdl(modelRdl);
+            }
+            finally
+            {
+                this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.EndUpdate));
+            }
+
             this.openReferenceDataLibraries.Remove(modelRdl);
             this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.RdlClosed));
         }
@@ -1171,16 +1205,21 @@ public async Task CloseIterationSetup(IterationSetup iterationSetup)
         {
             this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.BeginUpdate));
 
-            await this.Assembler.CloseIterationSetup(iterationSetup);
+            try
+            {
+                await this.Assembler.CloseIterationSetup(iterationSetup);
 
-            var iterationToRemove = this.openIterations.Select(x => x.Key).SingleOrDefault(x => x.Iid == iterationSetup.IterationIid);
+                var iterationToRemove = this.openIterations.Select(x => x.Key).SingleOrDefault(x => x.Iid == iterationSetup.IterationIid);
 
-            if (iterationToRemove != null)
+                if (iterationToRemove != null)
+                {
+                    this.openIterations.Remove(iterationToRemove);
+                }
+            }
+            finally
             {
-                this.openIterations.Remove(iterationToRemove);
+                this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.EndUpdate));
             }
-
-            this.CDPMessageBus.SendMessage(new SessionEvent(this, SessionStatus.EndUpdate));
         }
 
         /// <summary>
diff --git a/CDP4DalCommon/CDP4DalCommon.csproj b/CDP4DalCommon/CDP4DalCommon.csproj
index 153ded70..1e2a3127 100644
--- a/CDP4DalCommon/CDP4DalCommon.csproj
+++ b/CDP4DalCommon/CDP4DalCommon.csproj
@@ -5,7 +5,7 @@
       <Company>Starion Group S.A.</Company>
       <Language>latest</Language>
       <Title>CDP4DalCommon Community Edition</Title>
-      <VersionPrefix>27.2.0</VersionPrefix>
+      <VersionPrefix>27.2.1</VersionPrefix>
       <Description>CDP4 Common Class Library that contains common types for any CDP4 server and the CDP4Dal</Description>
       <Copyright>Copyright © Starion Group S.A.</Copyright>
       <Authors>Sam, Alex, Alexander, Nathanael, Antoine, Omar, Jaime</Authors>
diff --git a/CDP4JsonFileDal/CDP4JsonFileDal.csproj b/CDP4JsonFileDal/CDP4JsonFileDal.csproj
index aa030978..c8072216 100644
--- a/CDP4JsonFileDal/CDP4JsonFileDal.csproj
+++ b/CDP4JsonFileDal/CDP4JsonFileDal.csproj
@@ -4,7 +4,7 @@
     <TargetFrameworks>net48;netstandard2.0</TargetFrameworks>
     <Company>Starion Group S.A.</Company>
     <Title>CDP4JsonFileDal Community Edition</Title>
-    <VersionPrefix>27.2.0</VersionPrefix>
+    <VersionPrefix>27.2.1</VersionPrefix>
     <Description>CDP4 Json File Dal Plugin</Description>
     <Copyright>Copyright © Starion Group S.A.</Copyright>
     <Authors>Sam, Merlin, Alex, Naron, Alexander, Yevhen, Nathanael</Authors>
diff --git a/CDP4JsonSerializer/CDP4JsonSerializer.csproj b/CDP4JsonSerializer/CDP4JsonSerializer.csproj
index 9d84e1a9..574c812c 100644
--- a/CDP4JsonSerializer/CDP4JsonSerializer.csproj
+++ b/CDP4JsonSerializer/CDP4JsonSerializer.csproj
@@ -4,7 +4,7 @@
     <TargetFrameworks>net48;netstandard2.0</TargetFrameworks>
     <Company>Starion Group S.A.</Company>
     <Title>CDP4JsonSerializer Community Edition</Title>
-    <VersionPrefix>27.2.0</VersionPrefix>
+    <VersionPrefix>27.2.1</VersionPrefix>
     <Description>CDP4 JSON Serialization Library</Description>
     <Copyright>Copyright © Starion Group S.A.</Copyright>
     <Authors>Sam, Merlin, Alex, Naron, Alexander, Yevhen, Nathanael</Authors>
diff --git a/CDP4MessagePackSerializer/CDP4MessagePackSerializer.csproj b/CDP4MessagePackSerializer/CDP4MessagePackSerializer.csproj
index 53675bc1..5850fdd2 100644
--- a/CDP4MessagePackSerializer/CDP4MessagePackSerializer.csproj
+++ b/CDP4MessagePackSerializer/CDP4MessagePackSerializer.csproj
@@ -4,7 +4,7 @@
       <TargetFrameworks>net48;netstandard2.0</TargetFrameworks>
       <Company>Starion Group S.A.</Company>
       <Title>CDP4MessagePackSerializer Community Edition</Title>
-      <VersionPrefix>27.2.0</VersionPrefix>
+      <VersionPrefix>27.2.1</VersionPrefix>
       <Description>CDP4 MessagePack Serialization Library</Description>
       <Copyright>Copyright © Starion Group S.A.</Copyright>
       <Authors>Sam, Alex, Alexander, Nathanael, Antoine, Omar</Authors>
diff --git a/CDP4Reporting/CDP4Reporting.csproj b/CDP4Reporting/CDP4Reporting.csproj
index a3a5ad92..ff321289 100644
--- a/CDP4Reporting/CDP4Reporting.csproj
+++ b/CDP4Reporting/CDP4Reporting.csproj
@@ -4,7 +4,7 @@
      <TargetFrameworks>netstandard2.0</TargetFrameworks>
      <Company>Starion Group S.A.</Company>
      <Title>CDP4Reporting Community Edition</Title>
-     <VersionPrefix>27.2.0</VersionPrefix>
+     <VersionPrefix>27.2.1</VersionPrefix>
      <Description>CDP4 Reporting</Description>
      <Copyright>Copyright © Starion Group S.A.</Copyright>
      <Authors>Sam, Alex, Alexander</Authors>
diff --git a/CDP4RequirementsVerification/CDP4RequirementsVerification.csproj b/CDP4RequirementsVerification/CDP4RequirementsVerification.csproj
index 77db8ffc..cb61a091 100644
--- a/CDP4RequirementsVerification/CDP4RequirementsVerification.csproj
+++ b/CDP4RequirementsVerification/CDP4RequirementsVerification.csproj
@@ -4,7 +4,7 @@
     <TargetFrameworks>net48;netstandard2.0</TargetFrameworks>
     <Company>Starion Group S.A.</Company>
     <Title>CDP4RequirementsVerification Community Edition</Title>
-    <VersionPrefix>27.2.0</VersionPrefix>
+    <VersionPrefix>27.2.1</VersionPrefix>
     <Description>CDP4 Class Library that provides requirement verification</Description>
     <Copyright>Copyright © Starion Group S.A.</Copyright>
     <Authors>Sam, Alex, Alexander, Yevhen, Nathanael</Authors>
diff --git a/CDP4Rules/CDP4Rules.csproj b/CDP4Rules/CDP4Rules.csproj
index 4c2b1bd0..a68346e6 100644
--- a/CDP4Rules/CDP4Rules.csproj
+++ b/CDP4Rules/CDP4Rules.csproj
@@ -4,7 +4,7 @@
     <TargetFrameworks>net48;netstandard2.0</TargetFrameworks>
     <Company>Starion Group S.A.</Company>
     <Title>CDP4Rules Community Edition</Title>
-    <VersionPrefix>27.2.0</VersionPrefix>
+    <VersionPrefix>27.2.1</VersionPrefix>
     <Description>CDP4 Class Library that provides Model Analysis and Rule Checking</Description>
     <Copyright>Copyright © Starion Group S.A.</Copyright>
     <Authors>Sam, Alex, Alexander, Yevhen, Nathanael</Authors>
diff --git a/CDP4ServicesDal/CDP4ServicesDal.csproj b/CDP4ServicesDal/CDP4ServicesDal.csproj
index 8e3ff15e..bb7683a6 100644
--- a/CDP4ServicesDal/CDP4ServicesDal.csproj
+++ b/CDP4ServicesDal/CDP4ServicesDal.csproj
@@ -4,7 +4,7 @@
     <TargetFrameworks>net48;netstandard2.0</TargetFrameworks>
     <Company>Starion Group S.A.</Company>
     <Title>CDP4ServicesDal Community Edition</Title>
-    <VersionPrefix>27.2.0</VersionPrefix>
+    <VersionPrefix>27.2.1</VersionPrefix>
     <Description>CDP4ServicesDal Dal Plugin</Description>
     <Copyright>Copyright © Starion Group S.A.</Copyright>
     <Authors>Sam, Merlin, Alex, Naron, Alexander, Yevhen, Nathanael</Authors>
diff --git a/CDP4ServicesMessaging/CDP4ServicesMessaging.csproj b/CDP4ServicesMessaging/CDP4ServicesMessaging.csproj
index 5046abe9..c54ef965 100644
--- a/CDP4ServicesMessaging/CDP4ServicesMessaging.csproj
+++ b/CDP4ServicesMessaging/CDP4ServicesMessaging.csproj
@@ -4,7 +4,7 @@
     <TargetFrameworks>netstandard2.0</TargetFrameworks>
     <Company>Starion Group S.A.</Company>
     <Title>CDP4Common Community Edition</Title>
-    <VersionPrefix>27.2.0</VersionPrefix>
+    <VersionPrefix>27.2.1</VersionPrefix>
     <Description>CDP4 Services Messaging is a Class Library that contains clients and messages class that can be used for inter services communication</Description>
     <Copyright>Copyright © Starion Group S.A.</Copyright>
     <Authors>Sam, Alex, Alexander, Nathanael, Antoine</Authors>
diff --git a/CDP4Web/CDP4Web.csproj b/CDP4Web/CDP4Web.csproj
index 9a70060a..29c93954 100644
--- a/CDP4Web/CDP4Web.csproj
+++ b/CDP4Web/CDP4Web.csproj
@@ -5,7 +5,7 @@
         <LangVersion>latest</LangVersion>
         <Company>Starion Group S.A.</Company>
         <Title>CDP4Web Community Edition</Title>
-        <VersionPrefix>27.2.0</VersionPrefix>
+        <VersionPrefix>27.2.1</VersionPrefix>
         <Description>CDP4Web Dedicated Sdk for CDPServicesDal</Description>
         <Copyright>Copyright © Starion Group S.A.</Copyright>
         <Authors>Sam, Alex, Alexander, Nathanael, Antoine, Omar, Jaime</Authors>
diff --git a/CDP4WspDal/CDP4WspDal.csproj b/CDP4WspDal/CDP4WspDal.csproj
index bea2a923..aaffae00 100644
--- a/CDP4WspDal/CDP4WspDal.csproj
+++ b/CDP4WspDal/CDP4WspDal.csproj
@@ -4,7 +4,7 @@
     <TargetFrameworks>net48;netstandard2.0</TargetFrameworks>
     <Company>Starion Group S.A.</Company>
     <Title>CDP4WspDal Community Edition</Title>
-    <VersionPrefix>27.2.0</VersionPrefix>
+    <VersionPrefix>27.2.1</VersionPrefix>
     <Description>CDP4 WSP Dal Plugin</Description>
     <Copyright>Copyright © Starion Group S.A.</Copyright>
     <Authors>Sam, Merlin, Alex, Naron, Alexander, Yevhen, Nathanael</Authors>