It seems that some skype clients crashed randomly when making video calls to lync. Therefore Microsoft disabled the video calling feature a few days ago. Detials can be found here: http://community.office365.com/en-us/w/lync/video-calling-between-skype-and-lync.aspx
Lync-Skype Video Connectivity
There it is… http://blogs.skype.com/2014/12/05/skype-and-lync-deliver-video-calls/ Microsoft initially announced this feature on the Lync Conference early this year. Last Friday, on 5th December, Skype 7.0 has been released and with this version, video calls to Lync are possible. Be aware that an update for Android…