Font is not displayed in Snap applications? A broken font cache is the cause!
I have installed some applications in my openSuse Linux with Snap. Usually things that were not available directly from the package sources, e.g. Handbrake. Here I now had the problem that the font display did not work anymore. In all Snap applications only rectangles were displayed.
The problem in this case is the font cache, which somehow got broken. This seems to happen more often.
The following commands can be used to clear the cache.
fc-cache -r rm ~/.cache/fontconfig/* sudo rm -f /var/cache/fontconfig/*
Afterwards it worked again.
