I tried to open a font file (.ttf) on Fedora 34 KDE with its own Font Viewer, and got
an error message says “Could not read font”.
The font file has been used on Windows, Mac and other Fedora Spins with Gnome
Font Viewer installed.
Wonder what I had done wrong.
Also, is it possible to remove KDE Font Viewer and use Gnome Font Viewer instead?
flatpak install flathub org.gnome.font-viewer
It is broken for me too. I reported it some time back but nothing seems to happen, and I haven’t investigated further myself.
You don’t need to remove kfontview in order to install gnome-font-viewer. They can live happily side by side, even without resorting to flatpacks.
This major bug occurs when running under Wayland. A workaround is to set
QT_QPA_PLATFORM=xcb before starting kfontview so that it runs under X11/XWayland, see KDE bug 439470.