/vr/ - Retro Games

I'm having an issue with UDB
I defined a new thing in zscript using inheritance (so only the parts I want changed compared to the original). Specifically the "FloatingSkull" so that I can have another decoration with a new appearance but the same size otherwise. I don't want to overwrite the original floating rock so I defined a DoomEdNums in MAPINFO to give the new one a different editor number. The resulting pk3 loads without errors in GZDoom but when I try to actually add the new thing in UDB (open map -> load resources) I always get this warning as soon as the map loads
I searched online and saw I had to add gzdoom.pk3 as a resource (with the exclude from testing option marked). I did it and the warning is still there. Is this an issue with inheritance or is there a step I'm missing?