After Upgrading to 11 : many entries are created in recent log messages whenever a visitor views a forum: > Preprocess callback is not valid: Class "template_preprocess_forum_topic" does not exist.. | Type | theme | |------|-------| | Location | https://domain.tld/de/forums/allgemeines-forum?page=2 | | Message | Preprocess callback is not valid: Class "template_preprocess_forum_topic" does not exist.. | | Severity | Warning |