Broken Starting Area

[Kjarrigan]

Downloaded the (default) client after a year, to try it another time and I can't leave the starting area because the wizard is not there. Instead there is a black broken/wrongly loaded area:





Running on Ubuntu 20.04
Tried OpenJDK 16 (which worked flawlessly last year) and also tried OpenJDK17.

Also tried switching characters multiple times. Always the same issue.