Hello,
Did you manually edited that file?
This is what should contain:
<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "urn:fontconfig:fonts.dtd">
<fontconfig>
<description>Re-define fonts dirs sample</description>
<reset-dirs />
<dir prefix="xdg">fonts</dir>
</fontconfig>
On the other hand, with this
Use --no-sandbox when starting the AppImage from terminal …