[xwiki-devs] Difference between 3.1 and 4.2 for object's implementation in oldcore.

Hello, I'm trying to update our semantic extension for xwiki from 3.1 to 4.2 to be able to release this as an open-source finally. Now, it looks like something inbetween 3.1 and 4.2 changed in xwiki-platform-oldcore's com.xpn.xwiki.objects* since my current 4.2 setup complains a lot with a message like: Wrapped Exception: Error number 7006 in 7: Cannot find property class com.xpn.xwiki.objects.classes.SPARQListClass in MetaClass object The SPARQListClass is our implementation of the list class which provides dynamic list based on the supplied SPARQ query and which was of course working well on top of 3.1. I'm looking into all the classes in 4.2's com.xpn.xwiki.objects subdirectory but so far I'm not able to distill what change between 3.1 and 4.2 breaks our SPARQList. Any idea what's going wrong or where should I have a look is highly appreciated. Thanks! Karel