[Gtkradiant] GtkRadiant Linux issue

[Michel Coutisson]

Hello and greetings !
I want to make Doom3 mods using gtkradiant for Linux. The installation 
just went fine though when I launch the .exe I've got this error : I/O 
warning : failed to load external entity 
"/opt/gtkradiant/doom3.game/game.xl ink"
The GUI is displayed but all seems weird
Any advice is welcome ...
ps: i m a newbie so be fair :-D