Function ... called from ... should not be called from a Blueprint

Yesterday everything was ok, and today this error came out of nowhere:


I didn’t changed ANYTHING in these classes. After clicking ‘Compile’ this error is gone and everything is working correctly… But i don’t want to recompile it every time i restart editor. (I’ve tried to GetPlayerCharacter → Cast to Player but it didn’t helped - anyway, it was working perfectly yesterday)

Here is how this function looks like:

I’ve solved it like this:

In my Inventory class, I’ve created a new funtion “PerformItemDelete”, which calls this “DeleteItem” function. Now when i call “PerformItemDelete” instead of “DeleteItem” directly, the error is gone.
Anyway, it’s… Strange, especially that it was working with no problem before.