Comment 8 for bug 2058823

I had a similar problem several times when installing Ubuntu Budgie, where the Installer Window would just disappear at some point while I was answering the setup questions.

However, a workaround that seems to have worked for many in the r/Ubuntu subreddit (not Ubuntu-Budgie-specific, and which also worked for me) is to start the Live Session in safe graphics mode.

Hoping that helps to narrow things down.

BTW, at this point I don't have a valid crash log because of the aforementioned successful installation while running the Live Session in safe graphics mode.