diff --git a/src/main/java/cz/cvut/kbss/analysis/controller/util/RestExceptionHandler.java b/src/main/java/cz/cvut/kbss/analysis/controller/util/RestExceptionHandler.java
index 365b965..58cc339 100755
--- a/src/main/java/cz/cvut/kbss/analysis/controller/util/RestExceptionHandler.java
+++ b/src/main/java/cz/cvut/kbss/analysis/controller/util/RestExceptionHandler.java
@@ -48,7 +48,7 @@ public ErrorInfo handleValidationException(HttpServletRequest request, Validatio
 
         String errorMessage = e.getErrors()
                 .stream()
-                .map(DefaultMessageSourceResolvable::getDefaultMessage)
+                .map(err -> "%s %s".formatted(err.getObjectName(),  err.getDefaultMessage()))
                 .collect(Collectors.joining(",", "[", "]"));
 
         return new ErrorInfo(errorMessage, request.getRequestURI());
diff --git a/src/main/java/cz/cvut/kbss/analysis/dao/BaseDao.java b/src/main/java/cz/cvut/kbss/analysis/dao/BaseDao.java
index 4da95a7..ff8488e 100755
--- a/src/main/java/cz/cvut/kbss/analysis/dao/BaseDao.java
+++ b/src/main/java/cz/cvut/kbss/analysis/dao/BaseDao.java
@@ -302,4 +302,9 @@ public void removeAll(URI subjectURI, URI propertyURI, URI context){
                 .setParameter("context", context)
                 .executeUpdate();
     }
+
+    @Override
+    public Class<T> getType() {
+        return type;
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/cz/cvut/kbss/analysis/dao/GenericDao.java b/src/main/java/cz/cvut/kbss/analysis/dao/GenericDao.java
index 05b62e4..402c6fc 100755
--- a/src/main/java/cz/cvut/kbss/analysis/dao/GenericDao.java
+++ b/src/main/java/cz/cvut/kbss/analysis/dao/GenericDao.java
@@ -127,4 +127,9 @@ public interface GenericDao<T extends HasIdentifier> {
      * @param context
      */
     void deleteContext(URI context);
+
+    /**
+     * @return the type of the entity managed by this class.
+     */
+    Class<T> getType();
 }
diff --git a/src/main/java/cz/cvut/kbss/analysis/model/NamedEntity.java b/src/main/java/cz/cvut/kbss/analysis/model/NamedEntity.java
index d0e25ac..0ae0c23 100644
--- a/src/main/java/cz/cvut/kbss/analysis/model/NamedEntity.java
+++ b/src/main/java/cz/cvut/kbss/analysis/model/NamedEntity.java
@@ -16,7 +16,7 @@
 @Setter
 public class NamedEntity extends AbstractEntity{
 
-    @NotEmpty(message = "Name must not be empty")
+    @NotEmpty(message = "name is empty.")
     @ParticipationConstraints(nonEmpty = true)
     @OWLDataProperty(iri = Vocabulary.s_p_name)
     private String name;
diff --git a/src/main/java/cz/cvut/kbss/analysis/service/BaseRepositoryService.java b/src/main/java/cz/cvut/kbss/analysis/service/BaseRepositoryService.java
index 31d6b52..3e83fcd 100755
--- a/src/main/java/cz/cvut/kbss/analysis/service/BaseRepositoryService.java
+++ b/src/main/java/cz/cvut/kbss/analysis/service/BaseRepositoryService.java
@@ -262,7 +262,8 @@ public boolean existsInPersistenceContext(URI id) {
      * @throws ValidationException In case the instance is not valid
      */
     public void validate(T instance, Object ... groups) {
-        DataBinder binder = new DataBinder(instance);
+        DataBinder binder = new DataBinder(instance, getPrimaryDao().getType().getSimpleName());
+
         binder.setValidator(validator);
         BindingResult bindingResult = binder.getBindingResult();
 
diff --git a/src/main/java/cz/cvut/kbss/analysis/service/validation/NamedEntityValidator.java b/src/main/java/cz/cvut/kbss/analysis/service/validation/NamedEntityValidator.java
index 763dd82..58c7855 100644
--- a/src/main/java/cz/cvut/kbss/analysis/service/validation/NamedEntityValidator.java
+++ b/src/main/java/cz/cvut/kbss/analysis/service/validation/NamedEntityValidator.java
@@ -48,13 +48,13 @@ protected void customValidation(Object target, Errors errors, Object... validati
         NamedEntity entity = (NamedEntity) target;
 
         if(existsWithName(entity))
-            errors.rejectValue("name", "name.duplicate", "Duplicate entity name");
+            errors.rejectValue("name", "name.duplicate", "uri is not null nor unique.");
 
         if(groups.isCreateGroup() && exists(entity)){
-            errors.rejectValue("uri", "uri.exists", "The uri should be null or unique");
+            errors.rejectValue("uri", "uri.exists", "name already exists.");
         }
         if(groups.isUpdateGroup() && !exists(entity)){
-            errors.rejectValue("uri", "uri.not-exists", "Uri does not refer to an existing entity");
+            errors.rejectValue("uri", "uri.not-exists", "uri does not refer to an existing entity.");
         }
     }