System.InvalidOperationException: No valid techniques
   at OpenRA.GlRenderer.Shader..ctor(GraphicsDevice dev, Stream s)
   at OpenRA.GlRenderer.GraphicsDevice.CreateShader(Stream stream)
   at OpenRA.Graphics.Renderer..ctor()
   at OpenRA.Game.Initialize(Arguments args)
   at OpenRA.Program.Run(String[] args)
   at OpenRA.Program.Main(String[] args)