Can you please try doing the following?
0) Open a new empty scene.
1) Temporary disable “Auto Refresh” in Unity “Edit/Preferences/General”.
2) Set Unity “Project Settings/Editor/Asset Serialization Mode” to “Force Text” if not already.
3) Open up GraphOwner.cs and comment out line #302, reading: EditorApplication.delayCall += ()=>{ AssetDatabase.ImportAsset(AssetDatabase.GetAssetPath(graph)); };
4) Preferably try the updater in any version before Unity 5.5 please.
5) Considering all goes well, save project and re-enable “Auto-Refresh”.
Please let me know if that will work. If it still don’t and you want so, I can manually update your project if you are willing to send it to me for your convenience. Just let me know.
Gavalakis
