I took a screenshot of my Character Creation screen in the game and when I compared it with let's plays of the game, I saw that it's missing the numbers and stats. I am unable to control the stats, without altering every other stat simultaneously and I can't click Done and proceed to the actual game.
I changed the resolution to 1920x1080, then to 1280x720 and then back to 800x600 - nothing helped.

Does anyone know how I can fix this?

After installing Arx Libertatis, the problem's solved.