It tells you that you have written the file name wrong.
In your server.cs, you currently have this line:
exec("./Weapon_Rocket Launcher.cs");
But due to the file you included, it should be something like this:
exec("./Weapon_OriginalRL.cs");
However, I guess that is not the real name of the script. Either way, try to stay away to have whitespace characters, like space, in your filenames.