Request error (error): UnityEditor.AsyncHTTPClient:Done(State, Int32)

I am using unity Free latest patch, and I remember seeing this when I was downloading assets bought from the asset store. Now when I add prefabs to the scene and hit play it will play for a short bit then stop and pause and won't let me do nothing else. I read in the console for an error and I get this message. I have no idea how to fix it. Please help.