Bug 505840

SUMMARY
If you save an image as a filetype which will lose information, i.e. flatten the image, or need quality settings, like JPG, but cancel the window where you are warned about this or can provide this information, you receive an "Unknown error" message.

STEPS TO REPRODUCE
1. Run Krita
2. Start a new document
3. Press Ctrl+S to bring up the "Saving As - Krita" window
4. Type filename: 1.jpg
5. Click OK
6. Notice window "JPEG image - Krita" appears, with a quality slider and so on
7. Decide against saving in this format, so press Cancel on this window

OBSERVED RESULT
A dialog: "Could not save <filename>.jpg. Unknown error."

Clicking Show Details reveals "Could not start saving <filename>.jpg. Unknown failure has happened".

EXPECTED RESULT
The "JPEG image - Krita" window to close, and the "Saving As - Krita" window to reappear, with folder and filename etc. filled in as before, to allow the user to choose a different file format for example.

SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20250617
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.14.0
Qt Version: 6.9.1
Kernel Version: 6.15.2-1-default (64-bit)
Graphics Platform: X11

ADDITIONAL INFORMATION
Krita Version: 6.0.0-prealpha (git 79b3845)