As a part of my work I was playing with some internationalisation and changed my system language to German. I don’t speak German. When it came time to set everything back into English I found that my menu and system items had not got the message and continued to display most of their strings in German. I couldn’t find any way of forcing the language back to English via the system settings (everything was already back to English) and removing the German language did nothing to help.

After much Googling I found someone stating that removing /var/tmp/kdecache-username resolved their problem. Sure enough renaming my kdecache-username directory reset a whole bunch of stuff but really messed up some of the system settings that I really wanted to keep. After some trial and error I found that just removing /var/tmp/kdecache-username/ksycoca* got rid of the lingering German language problems and allowed me to keep the rest of my desktop settings as they were.

I have no idea if this is a bug in KDE or if there’s an option to reset the caching that is responsible for this problem.