If you built it with the previous SDK the most common bug came from copying items in SDK 11, or 10 or whatever. Previous versions didn’t note a copy.
That version added ‘copy’ to each iteration so if you did it over and over again the item name would display as - copy copy copy copy copy etc
The latest version changed that. Open up your project xml with notepad ++ and see if you still have the copy thing in there.
That tended to cause crashes when opening rather than saving but that’s the most obvious one to check first.