__WorldContext pin appears and doesn't let to save my Blueprint

It seems nothing listed in that topic helped me. But I found in external references a line

"BlueprintGeneratedClass /Engine/Transient.REINST_MyLib_C_119 (1)". 

MyLib is my functions library. It looks like library references itself.

Update: when I remove any invocation of function with __WorldContext pin, reload editor - this line with circular reference disappears.