Hi Scorpion99,
Thanks for following this thread.
Time is very important for SSL transaction. So please check the time setting according the order:
1. check the time zone
2. check the date
3. check the time
4. Press OK
5. Restart the computer, make sure the time is correct and check if the issue persists.
Additionally, please refer to the KB below to install the cumulative update to see if this helps:
A credential dialog box appears or an error message is received when you log on to Lync Online
http://support.microsoft.com/kb/2464810
A similar thread for your reference :
http://community.office365.com/en-us/forums/166/p/47516/168032.aspx
Thanks,
Linda Wang