Are you using Windows? If so, using your Windows file browser go to This PC -> Local Disk (C:) -> Users. In that folder you should see a folder named after your Windows username. Inside it should be a file named demonshymn2_log.txt. If you're able to find it, please attach it to an email and send it to email@example.com.
Otherwise thanks for the bug report- Even if I'm not exactly sure what the problem is, I'll try and add some backup method of drawing in the next version. Thank you!