During 2 days i had all the problems alot speak about here. Black/white screen, engine error: Unable to load client database / Mountappfilesystem() failed Miss some vtf files, some manifest,... And i finaly find something to launch the game. Go into your Tools list on Steam. Right click Source SDK Base 2007 and add in launch options: -game ..\empires\empires (if your Empires folder is in the same parent folder than Source SDK Base 2007, otherwise write the full path to empires\empires folder) Then launch Source SDK Base 2007. Enjoy EDIT: If you want to use full path and have a space in the path to Empires, don't forget to use quote (" ") Ex: -game "C:\Program Files (x86)\Steam\SteamApps\#folder where is Empires#\Empires\Empires"