Cannot see javascript files in Monodevelop Unity 5.2

Since upgrading to Unity 5.2 javascript files are not showing in the Monodevelop Solution explorer (see image below). Does anyone know how to resolve this issue?

I had this problem too.

Is the Unity->Preferences->External Tool->External Script Editor set to monodevelop (built-in)?

After I set this, restarted the Unity Editor and double-clicked a UnityScript (i.e. js) file in the Assets pad, I landed in MonoDevelop and suddenly the Assembly-UnityScript and Assembly-UnityScript-firstpass projects were there.