While working with soft brushes, or importing images, krita create artifacts that are mostly visiable on dark places, and they can't be smoothed with mixing brush. This problem is up just in Krita, other ones work good. This wasn't before. Reinstalling is not working.

The link you gave doesn't work, I'm afraid.

We'll need to see your layer stack and know which profile is assigned to the image.

I only using simple layers
https://sun9-7.userapi.com/c856524/v856524397/1cdb39/r8LJWxqhyVM.jpg

For some reason, srgb-elle-v2-10.icc is assigned as your image's profile, while it should have srgb-elle-v2-srgbtrc.icc for this color depth. You can either try to convert the image to srgb-elle-v2-srgbtrc.icc by going to image->convert image colorspace and selecting the profile there.

What is going on is that the profile you have right now is linear, and 8bit images don't have enough room for linear profiles, and most of the space is used up by the lighter tones. We tend to use 16bit or higher for linear images for that reason. So you will want to go to a non-linear profile like the one I suggested.

You might also have accidentally set the new image dialog to use this profile. Krita remembers that.

I did as you said and it is working, thank you very much for your help.