The other day I was struggeling with some strange errors on a Lync deployment I did for one of my customers.
The first was that some users did get this error:
After some help from a blogg I found the solution to this problem where we added the frontend server to the trusted site for Internet Explorer.
Thanks to http://communicationsknowledge.blogspot.no/2012/04/cannot-synchronize-with-corporate.html
The we had also an error where we got prompted for certificate and since my customer did not have a huge helpdesk to guide the users we added to the registry the following
This made my day and maked my customer very happy...........