I got around to upgrading my main laptop to Windows 8.1 this week (finally!) and found I was unable to open the Metro-version apps of both Lync and Skype. They would start to open, show me the splash screen, and then exit. After a bit of digging it appears the crash is caused by the display adapter driver. Seems like Intel still has some issues with their driver for the HD 4000 Graphics on 8.1 and there doesn't seem to a fix.
In case it saves someone else the time, I've already tried all of the following revisions, the latest of which was released less than two weeks ago:
- 184.108.40.20690 (Windows 8 version)
So you may want to hold off on that upgrade if you have an Intel HD 4000 chip and rely on Lync MX or Skype heavily.