Bonjour,
à la suite de rien de spécial, GMB ne démarre plus.
Voici ce que renvoie le terminal:


print() on closed filehandle $fifofh at /usr/bin/gmusicbrowser line 264.
GStreamer::Interfaces perl module not found -> visuals not available
Reading saved tags in /home/pascal/.config/gmusicbrowser/gmbrc ...
@Fields=album_shuffle replaygain_album_gain skipcount file grouping compilation replaygain_track_peak modif lastskip replaygain_reference_level genre embedded_pictures label title replaygain_album_peak album_artist samprate filetype bitrate missing added channel title_or_file size rating album_artist_raw lastplay shuffle playcount embedded_lyrics replaygain_track_gain extension track version path length artist album comment disc year barefilename fullfilename_raw artists first_artist album_picture album_years version_or_empty uri artist_picture rating_picture missingkey fullfilename at /usr/bin/../share/gmusicbrowser/gmusicbrowser_songs.pm line 965.
adding update code for artists at /usr/bin/../share/gmusicbrowser/gmusicbrowser_songs.pm line 1084.
Reading saved tags in /home/pascal/.config/gmusicbrowser/gmbrc ... done
These commands were not found : mpg123, flac123, mpg321
=> these file types won't be played by the 123 output : mp3
DisplayFromGID_sub(genre)

Es ce que le programe se termine ? Autrement dit, es ce que tu as une "invite" (genre "pascal:~$") après avoir affiché tout ça.
Il est possible que tout marche bien, sauf que la fenêtre est cachée d'une façon ou une autre.
Essaye de lancer dans un autre terminal une de ces commandes pendant que l'autre marche :
echo PlayPause > ~/.config/gmusicbrowser/gmusicbrowser.fifo
echo ShowHide > ~/.config/gmusicbrowser/gmusicbrowser.fifo