Launcher not loading correctly

Well ... if you are not sure this is affected by your 'custom theme', why not try it without that.

Also provide details on what you did to your system to break it so horribly please 🙂

it works fine without the theme, and i didn't break my system, its red because i use the red district theme.

It is the custom themes, I have the same issue. https://mojang.atlassian.net/browse/MC-14175