Try to save as or to export on a target that already exists to override it. You will get a pop-up error like so: Could not save /**/target.png Reason: /**/target.png cannot be written to. Please save under a different name. STEPS TO REPRODUCE 1. Save AS or Export on an existing file macOS: big sure git branch: krita/4.3 commit: 3740597f3b0220232d7cf0f99cc6f6b56ed028f8
Works here... Krita asks whether it should overwrite the existing file, and if I say yes, it works. Tested on big sur as well.
bummed. Let me restart my machine...
My bad, it just worked after restarting the OS... Closing the issue!