I have 38" 21/9 WQHD+ (3840 x 1600) and placed the EXE on the Desktop. No other fancy configs though. Weirdly enough, the executable did not have an icon, perhaps, that's related?
It does work for me on the desktop. So it’s likely some hardware or driver issue. Is there anything interesting in %appdata%\CAT & ONION\log.txt ? If it even exists, not sure if had enough time to write out the log if the program crashed.