If you are using MS outlook 2010 and noticed something different around or after 12/8/15 please read this article. It seems Microsoft had a major issue with a update (#4409) and it caused outlook to only open in safe mode. The article points you to a MS page that tells you how to remove the patch to fix this.

http://www.infoworld.com/article/3013219/microsoft-windows/microsoft-pulls-botched-patch-kb-3114409-that-triggered-problems-with-outlook-2010.html