Hey Gochida-
Thank you for providing the project again. This time I was able to open the project and investigate. I found that the issue was in fact a null pointer, the CurrentWidget variable was not set. If you make the pointer public and add EditAnywhere, Instanced, BlueprintReadWrite, Category = Test inside the UPROPERTY declaration, this will allow you to set any widget in your content browser to the pointer. After you’ve set the pointer in your game mode blueprint, you should be able to play without the crash occurring.
Cheers