diff --git a/build.gradle b/build.gradle
index bceb03c3..b165df33 100644
--- a/build.gradle
+++ b/build.gradle
@@ -65,10 +65,7 @@ allprojects {
         maven { url "https://maven.theepicblock.nl" }
         maven { url "https://lazurite.dev/maven/releases" }
         maven { url "https://repo.opencollab.dev/maven-snapshots/" }
-        maven {
-            name = 'Ladysnake Mods'
-            url = 'https://ladysnake.jfrog.io/artifactory/mods'
-        }
+        maven { url 'https://maven.ladysnake.org/releases' }
         mavenLocal()
     }
 
diff --git a/gradle.properties b/gradle.properties
index 9a9f3dc1..5cfc6c8a 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -12,7 +12,7 @@ fabric_version=0.83.0+1.20.1
 
 maven_group = eu.pb4
 
-mod_version = 0.5.6
+mod_version = 0.5.7
 
 minecraft_version_supported = ">=1.20-"
 
diff --git a/polymer-core/src/main/java/eu/pb4/polymer/core/api/item/PolymerItemGroupUtils.java b/polymer-core/src/main/java/eu/pb4/polymer/core/api/item/PolymerItemGroupUtils.java
index 9a5e3e08..75afd9a2 100644
--- a/polymer-core/src/main/java/eu/pb4/polymer/core/api/item/PolymerItemGroupUtils.java
+++ b/polymer-core/src/main/java/eu/pb4/polymer/core/api/item/PolymerItemGroupUtils.java
@@ -34,7 +34,14 @@ public static Contents getContentsFor(ServerPlayerEntity player, ItemGroup group
     }
 
     public static Contents getContentsFor(ItemGroup group, RegistryWrapper.WrapperLookup lookup, FeatureSet featureSet, boolean operator) {
-        return ((ItemGroupExtra) group).polymer$getContentsWith(featureSet, operator, lookup);
+        try {
+            return ((ItemGroupExtra) group).polymer$getContentsWith(featureSet, operator, lookup);
+        } catch (Throwable t) {
+            // Some 1.20 mods use client classes in their item groups because vanilla doesn't call them on the server anymore
+            // Catch instead of letting the game crash, even though it's their fault...
+            PolymerImpl.LOGGER.warn("Failed to load contents for an ItemGroup", t);
+            return new Contents(List.of(), List.of());
+        }
     }
 
     /**