For that first issue, not really sure. Sounds like Itch doing Itch things, not sure why.
As for the second, this issue has come to my attention and I'm working on fixing it now. I'll have it released soon. In the meantime, you can get around the issue by pressing "Ignore" on the error window, which will take you to the start of the game and from there you can load saves or just go back to the main menu. You can also avoid getting the error again by going into settings, scrolling down, and changing the menu theme to any of the ones listed. Sorry for the trouble, and thanks for the heads up.