Certificate error while loading PPT in Lync 2013
If you are getting Certificate error( There was a problem verifying the certificate from the server. Please contact your support team ) while loading PPT in lync 2013, then uncheck the following Internet Setting and try again. Internet Options -> Advanced -> Security(Check for server certificate revocation) And if the above setting doesn't work then make sure the root certificate for WAC(office web apps) and Lync server is exchanged correctly.