See https://docs.krita.org/KritaFAQ#Krita_starts_with_a_black_or_blank_canvas_and_nothing_changes_when_you_try_to_draw.2Fshows_a_black_or_blank_screen_on_my_Windows_system_with_an_Intel_GPU
There are three problems:
* a crash when compiling a shader
* a black screen
* a blank canvas that only updates when the user clicks outside the canvas
The first two problems seem to happen with drivers that are not up to date. The other problem seems to happen with recent Windows updates.