nathan@ns-homedesktop1-ub:~/OpenRA$ mono OpenRA.Game.exe Game.Mods=ra
Invalid mod: aftermath
Invalid mod: d2k

Unhandled Exception: System.InvalidOperationException: No valid techniques
  at OpenRA.GlRenderer.Shader..ctor (OpenRA.GlRenderer.GraphicsDevice dev, System.IO.Stream s) [0x00000] in <filename unknown>:0
  at OpenRA.GlRenderer.GraphicsDevice.CreateShader (System.IO.Stream stream) [0x00000] in <filename unknown>:0
  at OpenRA.Graphics.Renderer..ctor () [0x00000] in <filename unknown>:0
  at OpenRA.Game.Initialize (OpenRA.Arguments args) [0x00000] in <filename unknown>:0
  at OpenRA.Program.Run (System.String[] args) [0x00000] in <filename unknown>:0
  at OpenRA.Program.Main (System.String[] args) [0x00000] in <filename unknown>:0