Matrix 4x4 Error, MissingFieldExeption

I recently started a new project on Unity and i was going to import a gui script which i had previously used. When ran the game this erroris spammed every tick and the gui is not visible.

 MissingFieldException: GUI.matrix
 Boo.Lang.Runtime.DynamicDispatching.PropertyDispatcherFactory.FindExtension (IEnumerable`1 candidates)
 Boo.Lang.Runtime.DynamicDispatching.PropertyDispatcherFactory.Create (SetOrGet gos)
 Boo.Lang.Runtime.DynamicDispatching.PropertyDispatcherFactory.CreateSetter ()
 Boo.Lang.Runtime.RuntimeServices.DoCreatePropSetDispatcher (System.Object target, System.Type type, System.String name, System.Object value)
 Boo.Lang.Runtime.RuntimeServices.CreatePropSetDispatcher (System.Object target, System.String name, System.Object value)
 Boo.Lang.Runtime.RuntimeServices+<SetProperty>c__AnonStorey18.<>m__D ()
 Boo.Lang.Runtime.DynamicDispatching.DispatcherCache.Get (Boo.Lang.Runtime.DynamicDispatching.DispatcherKey key, Boo.Lang.Runtime.DynamicDispatching.DispatcherFactory factory)
 Boo.Lang.Runtime.RuntimeServices.GetDispatcher (System.Object target, System.String cacheKeyName, System.Type[] cacheKeyTypes, Boo.Lang.Runtime.DynamicDispatching.DispatcherFactory factory)
 Boo.Lang.Runtime.RuntimeServices.GetDispatcher (System.Object target, System.Object[] args, System.String cacheKeyName, Boo.Lang.Runtime.DynamicDispatching.DispatcherFactory factory)
 Boo.Lang.Runtime.RuntimeServices.SetProperty (System.Object target, System.String name, System.Object value)
 GUI.OnGUI () (at Assets/GUI.js:11)

The same script works on another project of mine so i dont see why its not working now. I know little about Matrix 4x4 so any help is appriciated ^^