diff --git a/backend/src/Squidex.Domain.Apps.Entities/Contents/ContentChangedTriggerHandler.cs b/backend/src/Squidex.Domain.Apps.Entities/Contents/ContentChangedTriggerHandler.cs
index 5ba06184a..00fcbe188 100644
--- a/backend/src/Squidex.Domain.Apps.Entities/Contents/ContentChangedTriggerHandler.cs
+++ b/backend/src/Squidex.Domain.Apps.Entities/Contents/ContentChangedTriggerHandler.cs
@@ -168,7 +168,7 @@ namespace Squidex.Domain.Apps.Entities.Contents
             {
                 foreach (var schema in trigger.Schemas)
                 {
-                    if (MatchsSchema(schema, @event.SchemaId) && MatchsCondition(schema, @event))
+                    if (schema != null && MatchsSchema(schema, @event.SchemaId) && MatchsCondition(schema, @event))
                     {
                         return true;
                     }