Having this issue with Dolphin on i3 too. Pretty annoying, so I’m using XnViewMP in the meantime.
It looks like the only fix that works is the one from the Arch Linux forum, but I’m not entirely sure how to go about it. I’ve downloaded the plasma-applications.menu file from GitHub, and placed it into /.config/menus but that doesn’t do anything when I run kbuildsycoca6/kbuildsycoca5 as I still get a file missing error.
Wondering if I should also place it in /etc/xdg/menus as well, seeing as it is also missing from that location. But I’m hesitant to do it because an update may delete the file anyway.
EDIT: It worked?! Meaning downloading the file and placing it into
/.config/menusstarted working after reloading my i3 in-place. Hopefully, it’s not temporary.
It seems to be temporary indeed. I locked my i3 for about 30 minutes, and when I unlocked it and right-clicked a file in Dolphin it again didn’t show any appropriate apps to open files with. Did another reload in-place and it’s working again…