I heard rumors that Epic was working on a BP to C++ converter, but I don’t think it’ll be available any time soon. If you want to do it that way, you have to do it by hand.
Have you tried re-parenting your gameinstance to the c++ gameinstance and make sure the project defaults to yours? That way you can keep all your BP’s the way they are, but still use all the functionality of the C++ version.
yes however there is already c++ in the game and it is my current game instance i need to change my game instance to a blueprint one for the login but if i change game instance the game does not work?!