Mirror Reflection Shader v4 in Unity 5. Any success anyone?

After upgrading to Unity 5 I had to switch to the new the new version of the mirror reflection shader available here: http://wiki.unity3d.com/index.php/MirrorReflection4

However the new shader is giving me a 'could not find entry point' error when the older v3 worked just fine in Unity 4. Is this a bug or am I missing something? I only managed to get around it by replacing it with the 'Fx/Water' shader but I can't get a pure mirror effect from it. Has anyone had any success with the original shader yet in Unity 5?