diff --git a/backend/src/Squidex.Domain.Apps.Core.Model/Rules/EnrichedEvents/EnrichedCommentEvent.cs b/backend/src/Squidex.Domain.Apps.Core.Model/Rules/EnrichedEvents/EnrichedCommentEvent.cs
index f4e1f5a61..d5a50418f 100644
--- a/backend/src/Squidex.Domain.Apps.Core.Model/Rules/EnrichedEvents/EnrichedCommentEvent.cs
+++ b/backend/src/Squidex.Domain.Apps.Core.Model/Rules/EnrichedEvents/EnrichedCommentEvent.cs
@@ -25,7 +25,7 @@ namespace Squidex.Domain.Apps.Core.Rules.EnrichedEvents
         [IgnoreDataMember]
         public override long Partition
         {
-            get => MentionedUser.Id.GetHashCode();
+            get => MentionedUser?.Id.GetHashCode() ?? 0;
         }
 
         public bool ShouldSerializeMentionedUser()
diff --git a/backend/src/Squidex.Domain.Apps.Core.Model/Rules/EnrichedEvents/EnrichedSchemaEvent.cs b/backend/src/Squidex.Domain.Apps.Core.Model/Rules/EnrichedEvents/EnrichedSchemaEvent.cs
index 46136427b..82a940be9 100644
--- a/backend/src/Squidex.Domain.Apps.Core.Model/Rules/EnrichedEvents/EnrichedSchemaEvent.cs
+++ b/backend/src/Squidex.Domain.Apps.Core.Model/Rules/EnrichedEvents/EnrichedSchemaEvent.cs
@@ -20,7 +20,7 @@ namespace Squidex.Domain.Apps.Core.Rules.EnrichedEvents
 
         public override long Partition
         {
-            get => SchemaId.GetHashCode();
+            get => SchemaId?.GetHashCode() ?? 0;
         }
     }
 }
diff --git a/backend/src/Squidex.Domain.Apps.Core.Model/Rules/EnrichedEvents/EnrichedUsageExceededEvent.cs b/backend/src/Squidex.Domain.Apps.Core.Model/Rules/EnrichedEvents/EnrichedUsageExceededEvent.cs
index 619b4beda..c9794bc60 100644
--- a/backend/src/Squidex.Domain.Apps.Core.Model/Rules/EnrichedEvents/EnrichedUsageExceededEvent.cs
+++ b/backend/src/Squidex.Domain.Apps.Core.Model/Rules/EnrichedEvents/EnrichedUsageExceededEvent.cs
@@ -15,7 +15,7 @@ namespace Squidex.Domain.Apps.Core.Rules.EnrichedEvents
 
         public override long Partition
         {
-            get => AppId.GetHashCode();
+            get => AppId?.GetHashCode() ?? 0;
         }
     }
 }