Hello!
I downloaded Krita just last week, I have the 4.0.0 version, and I enjoy it. Although I've had few problems with it, today has brought a lot of frustration.

Whenever I try and pick a new colour on the colour wheel, the program suddenly crashes. (On my drawing tablet it's instant, while with the mouse it takes a few clicks.) I suspect this has something to do with me changing the colour model type to HSY', as it only started crashing after I changed it. However, I can't be certain that it's the cause, as whenever I try to switch it back to HSI, or another type, guess what?

I've now tried reinstalling Krita, and even getting an older version, but those somehow saved the presets that I assume made it crash, and is still crashing, so I'm screwed. Help.

Thank you!
-Me

Try to see if you can get a backtrace, and if so, report a bug with said backtrace to bugs.kde.org under the product Krita.