Xamarin can't build portable class library - can't target necessary frameworks

Question

We are using Xamarin for mobile apps development, however things are a bit complicated, when we try to share code. When someone makes changes to the project and you pull them, usually you are in for a bit of a headache regarding references.

With latest issue things got a bit stanger so I decided to post a question here in hope to resolve this.

It's the same project, two different computers, both using profile49, but my can't target all the frameworks.

Here are the images of the situation.

On computer where it works

On computer where it doesn't work

Maybe it's worth mentioning that both uses VS2012. Working computer uses windows 8 and not working 8.1. Both have Xamarin installend (iOS and Android).

Any ideas what's happening?

Answer 1

The most likely reason for this is that you installed Xamarin before Visual Studio or an update to Windows / Visual Studio replaced the entire C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETPortable directory, thus removing the Xamarin.Android.xml and Xamarin.iOS.xml files.

Reinstalling Xamarin fixes this, though repairing should work as well (go to Control Panel / Programs and Features, then right-click Xamarin.Android or Xamarin.iOS and select "repair").