I am using KDE Neon
Everything was fine until i got an update that messed up fonts and icons in librewolf, firefox, and firefox dev edition
This is how firefox looks like
As you can see, some of the icons are missing, like the previous page icon on the left.
Font is messed up and some letters are missing.
Notes:
When i restart firefox in troubleshoot mode, the problem disappears.
Not all web pages has this problem, most web pages look normal and no missing letters.
I tried disabling all extensions one by one but no positive effect.
If you’re signed in and synchronised, then you can delete the .cache and the profile and start fresh - sign in and synchronise again… Firefox will build it anew, and you’ll be sure nothing’s corrupt that way.
Synchronised data always comes back, but old profiles don’t always get along with new versions of Firefox… I can’t remember the last time I needed to do it, but it certainly worked for me a year or three back.
1 Like
Will try that
But my firefox dev edition and librewolf are privacy focused and not synced at all
Yet they have the same problem
I think the update messed up a font or did something system wide that affects firefox browsers
For instance this is libreworf
icons are missing !!
This is a problem generally caused by the operating system changing the fontconfig in a way that breaks apps. It’s not a KDE problem.
…Except if you’re using a KDE operating system like Neon, then it is our problem. 
2 Likes
Any idea how to try and fix this
Sometimes i can figure out the places of the characters, other times it’s very hard to read some pages
This problem only affecting the browsers
HAPPENED AFTER AN UPDATE
I have another KDE Neon computer and same thing happened there
Tried ChatGPT recommendations, but none of them worked
Summary
1. Reset Firefox Profile and Cache
rm -r ~/.cache/mozilla/firefox
mv ~/.mozilla/firefox ~/.mozilla/firefox.backup
2. Check System’s Font Configuration
sudo apt install --reinstall breeze-icon-theme
3. Clear System Cache and Rebuild Databases
sudo update-mime-database /usr/share/mime
sudo update-desktop-database
rm -r ~/.cache/
