Runtime error on bind function to delegate

You should have the same params on function and delegate. It is strange that you didnt had a compilation error.

Someting like this:

in .h

DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FMySignature, bool, IsOk, AActor*, MyActor); //"," between type and variable name

UFunction() //do not forget that
void MyActor::Bar(bool IsOk, AActor* MyActor){};

FMySignature OnEvent;

in .cpp

OnEvent.Broacast(b, MyActor);