Have you tried to rebuild the solution in your text editor, prior to opening up the project?
Sometimes compiling the code will work (as far as the compiler goes), but it will cause the editor to crash. As the project reloads that code, it continues to crash until the code is rebuilt.
EDIT:
Actually… it doesn’t look like you are setting the “SkeletalMesh” variable in BeginPlay, so it is referencing a nullptr. You need to set that prior to accessing it by using this->GetMesh();