Rebuild the code, it will delete all modules DLLs, object files (unlinked machine code) and generated code and redo them again. This is also fixes mystries random unexplainabale crashes, sometimes object files lose compatibility when they are partly recompiled and it causes crashes.
Watch out if you got UE4 from source, rebuild will also delete engine module DLLs and EXEs, to prevent that in project settings in VS, in NMake section in rebuild command path add “-rocket” at the end.
The problem was a little more complex. I was typedef-ing nested containers. Something which Unreal doesn’t like apparently. So It wouldn’t generate the files again, even if I would rebuild. But, once I got it all sorted out, it worked. Thanks!