See attached. If the hex value in the filename before the extension is a letter, the program assumes it will be uppercase and fails. I manually renamed 0000000d.app to 0000000D.app etc and the program ran successfully.

Thanks for keeping Linux users in mind! The program works great otherwise.

Edit: I saw a similar report on gbatemp and you reported this fixed. Just to be clear, I hit this problem on a fresh git pull this afternoon (Jan 1st). Seems like a lingering bug remains.