Hi, We have a sharepoint 2010 farm, and had OCS 2007. With this setup, we could perfectly see the presence status of the users in sharepoint document libraries and other locations. We have recently upgraded to Lync 2010, and now the presence status is not working anymore. For some users I see the Lync status (online, offline, busy, away...) but not for all users. For these users I just get 'Presence unknown'. Other users also have this problem, but the persons they can or can't see sometimes differ. For example Person A sees person B as online, but person C just gets 'Presence unknown' for person B. Also for the user for which we can see the status, the Lync pictures are not showing up. Has anyone experienced some issues like this? Edit to add: the presence status is working fine in other programs like Outlook. Things I did to try to solve this problem -reinstall Lync client on pc -reboot sharepoint server -add sites to trusted sites Thijs