I'm new to unraid, but pretty shocked that this issue is still present as of 2022-07-24.
Have an accent character in my windows username and just kept getting failures setting up the installer with no helpful error messages.
I mean, do I trust my data with this? can't even program an installer that works outside US of A? and not fixing a install blocker years later?
Not a good look. In fact if I was in a serious setting this experience already disqualified unraid for any serious use.