Thanks for Your answer but like i say:
“For simplicity, let me add that first I checked the obvious possibilities of errors, reinstalled the engine, played VS files, cleaned the project folders.”
So problem still exist.
Also. there is no problem with loading plugin itself. Plugins load correctly, because they works in editor. I think theyre loaded too late after BP compiles, but i dont have idea how to fix it.
Like i say when i Reload BP asset all plugin classes works fine. 0 errors. But all fails after restart editor or packange atempt.