Invalid license. Please reactivate Xamarin.Android (XA9999)
Unable to determine license edition. (XA9010)
These messages can appear in a few different circumstances.
The current license on disk might be out-of-sync with the current user information on the computer. Refreshing the license files will resolve this problem in many cases.
The computer might have 2 conflicting duplicate activations. You can perform an initial check for this problem by looking on https://store.xamarin.com/account/my/subscription/computers for duplicates of the same computer name. If you see any duplicates, you can deactivate them as described on http://kb.xamarin.com/customer/portal/articles/1641743-manually-refresh-xamarin-licenses.
"Failed to load Android Entitlements"
Mono.VisualStudio.Shell.ShellPackage Error: 0 : Failed to load Android entitlements: Invalid license. Please reactivate Xamarin.Android (XA9999)
Mono.VisualStudio.Shell.ShellPackage Error: 0 : Failed license update: Invalid license. Please reactivate Xamarin.Android (XA9999)
This is an older version of the "Invalid license" problem from above. The same troubleshooting steps apply.
"This version was released after your subscription expired"
Error XA9000: This version was released after your subscription expired (11/11/2014 5:11:41 PM). (XA9000) (Mobile.Android.Utilities)
Error XA9010: Unable to determine license edition. (XA9010) (Mobile.Android.Utilities)
These messages commonly appear in two situations:
The on-disk licenses are outdated. Refreshing the license files will resolve this problem in many cases.
The Xamarin subscription is no longer active, and the current installed version of Xamarin is more recent than the expiration date of the subscription. In this case the correct fix is to downgrade to a version of Xamarin that was released before the subscription expired. Feel free to send an email to firstname.lastname@example.org to request the latest valid version for your subscription. If you still see the error after downgrading, be sure to try refreshing the license files too.
Knowledge base article about refreshing licenses: http://kb.xamarin.com/customer/portal/articles/1641743-manually-refresh-xamarin-licenses
Knowledge base article about downgrading: http://kb.xamarin.com/customer/portal/articles/1699777-downgrading
List of "XA" error codes: http://developer.xamarin.com/guides/android/troubleshooting/errors/
List of "MT" error codes: http://developer.xamarin.com/guides/ios/troubleshooting/mtouch-errors/
If the suggested steps don't resolve the problem you're seeing, or if you notice any other mistakes in the document, please let us know by writing to email@example.com or to one of your support email addresses listed on https://store.xamarin.com/account/.