When I installed the 2.0.21 version of yappari, I got this same problem. I managed to solve it by erasing the /home/user/.config/scorpius directory. That is re-created when yappari starts again. Perhaps this solves your problem. But recommend creating a copy of this directory before. You can rename it if you prefer. If this solve your case, I think it may be a configuration issue that may be causing the error and closing yappari.