It’s only seemed to happen with png so far. On fedora 38 GNU/Linux. If I press ctrl + z a few times, it will suddenly close the program without any error messages. I don’t believe this happens on windows either. I’m using the appimage, the latest stable appimage. Not the beta or RC for 5.2. I have here a webm of me doing random stuff to a mickey mouse png to demonstrate what happens when I press ctrl + z a few times to undo edits. At the very end, is when it closes back to desktop without any error message.
If it makes a difference, I’m on X11 GNOME 44, haven’t yet tested what happens under wayland. It didn’t seem to happen if I used a webp strangely.
I would advice you to try the 5.2 appimage in a way which will not affect your stable version. And see if the bug is reproducible in it. If it is then we should file a bug report in bugs.kde.org with the log files. The way to share log files are explained here - Getting Krita logs — Krita Manual 5.2.0 documentation
I will explain how to run the 5.2 appimage such that it will not hamper your main stable install.
Move the downloaded file in a new folder where you want to base your testing appimage to be. it can be anywhere.
Rename the downloaded appimage as just “testRC” without any extension and make it executable
Add a new folder besides the “testRC” appimage file with the name “testRC.home” - This will tell krita to use the folder “testRC.home” as the folder to store all the settings files so that it doesn’t affect your actual settings and resource file.