Hey Rudy, i will update to 4.8.1 now and will let you know.
Edit: The problem still persists in 4.8.1. What screenshots do you need ? I have a BaseSlot widget that derives from UserWidget, from that class i derive into SingleSlot (for slots with room for 1 item) and ItemTableSlot (for slots in a table of items). SingleSlot has 3 widgets that derive from it and ItemTableSlot has 1 widget. When i run the game i get this error:
I have to press the Compile button in both SingleSlot and ItemTableSlot to get it working, even though i have the green check on it from the beginning.