An unexpected error has occured while updating required files
The bug I had I had the same problem here on a fresh install of Win10 Full visual studio community 2015 update 3 . Creating a new project Xamarin Native (i Os Androird) shows up the same message as mentioned by Mike J.In addition, running in debug F5 makes the designer have a new popup Problem seems to appear also here https://bugzilla.xamarin.com/show_bug.cgi?
Solution: Try increasing the post limit on the plugin’s Settings page to be 10-15 higher than the number of posts you are trying to display.I had exactly the same problem described (on a new PC, with a new Visual Studio install) and am 99.9% sure the answer is in how updates are applied. The Xamarin framework is really not transparent about this at all.