can't open djvu format endless os flatpack ~$ flatpak run org.kde.okular Gtk-Message: Failed to load module "canberra-gtk-module" Gtk-Message: Failed to load module "canberra-gtk-module" Qt: Session management error: Could not open network socket org.kde.okular.core: No plugin for mimetype '"image/vnd.djvu+multipage"'. AL lib: (EE) ALCplaybackAlsa_open: Could not open playback device 'default': Connection refused AL lib: (EE) ALCplaybackAlsa_open: Could not open playback device 'default': Connection refused org.kde.knotifications: Audio notification requested, but sound file from notifyrc file was not found, aborting audio notification ~$
I've just published a new build of okular in flathub that will fix this.