Fix serialization of custom exceptions.

OpenRA.Utility/Program.cs

@@ -11,9 +11,11 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Runtime.Serialization;
 
 namespace OpenRA.Utility
 {
+	[Serializable]
 	public class NoSuchCommandException : Exception
 	{
 		public readonly string Command;
@@ -22,6 +24,12 @@ namespace OpenRA.Utility
 		{
 			Command = command;
 		}
+
+		public override void GetObjectData(SerializationInfo info, StreamingContext context)
+		{
+			base.GetObjectData(info, context);
+			info.AddValue("Command", Command);
+		}
 	}
 
 	class Program