Visual Studio: package did not load correctly after update extension.

If you get something similar to this:

package [XamarinAndroidPackage]Source: 'Xamarin.AndroidTools' Description: Method not found: 'Void Mono.AndroidTools.AnalyticsService.ReportContextProperty(System.String[], System.String[])'. System.MissingMethodException: Method not found: 'Void Mono.AndroidTools.AnalyticsService.ReportContextProperty.....

This might be caused by one of the common issues Visual Studio can run into with updating extensions according to https://bugzilla.xamarin.com/show_bug.cgi?id=44162 and it's right!

The solution is to Clear MEF Component Cache! Clearing the ComponentModelCache folder might help.  See step 3 on the following guide:
https://developer.xamarin.com/guides/cross-platform/getting_started/visual_studio_with_xamarin/troubleshooting/uninstall-xamarinvs/ 

Also there is a Visual Studio extension to make you life easier:
https://visualstudiogallery.msdn.microsoft.com/22b94661-70c7-4a93-9ca3-8b6dd45f47cd

This extension clears the MEF cache on disk and lets Visual Studio rebuild it. The reason for clearing the MEF cache is that it can become corrupted. This ususally happens when installing or updating extensions or other Visual Studio components.

Typical errors that can be solved by clearing the component cache are:

• Could not load package exception
• Could not load assembly exception
• Composition error when opening files
• Missing syntax highlighting of some languages in VS

Continuous integration using Visual Studio Online and a Bitbucket repository

Continuous integration using Visual Studio Online and a Bitbucket repository is not a straightforward task, it's not hard but definitely not straightforward.

Continuous integration is the practice to build your code everytime any member of your dev team integrates code changes to the main repository.

Integrate Visual Studio Online with Bitbucket requires a couple of thing:

1. You need to create a web app (aka proxy*) that ueue a new build using Visual Studio Team Services REST APIs
2. You need to configure a Bitbucket webhook to queue a new build  using the proxy. FYI webhooks "provide a way to configure Bitbucket Cloud to make requests to your server (or another external service) whenever certain events occur in Bitbucket Cloud".
3. Configure a new build in VSO that gets the code from an external Git repository

*You need to use a proxy because bitbucket webhooks only do a POST to an URL without any configuration options.

Also you can create a VSO webhook to notify slack (and also the dev team) the result of the build