The My Movies team have updated the Windows Media Center version of the My Movies addin. Version 4.05 Build 6 fixes issues adding categories to Media Center, fixes an installer issue on Windows Server 2012 Essentials and has changes to personal data saving in specific regions.
You can get the app from MyMovies.dk
My Movies for Windows Media Center and My Movies Collection Management 4.05 – Build 6
Fix: Issue preventing saving personal data on some machines with specific regional settings.
Fix: The installer was not being blocked on Windows Server 2012 Essentials, which could cause problems for the Home and Essentials product.
Fix: Adding categories to titles inside Windows Media Center did not automatically synchronize to the online service.