Failed to verify client cookie Over the past %1 minutes Lync Server has failed to validate cookie presented by the clients ...

Failed to verify client cookie

Over the past %1 minutes Lync Server has failed to validate cookie presented by the clients %2 time(s). The last such client which failed validation was "%3".
Cause: This can occur if the Web Conferencing Server and Web Conferencing Edge Server machine time(s) are out of sync. This can also be the result of a client attempting to connect to Web Conferencing Server without having the appropriate permissions.
Resolution:
Check to make sure that the Web Conferencing Server and Web Conferencing Edge Server machines and verify that the connection came from a trustworthy client. This could indicate an attack being by a rogue client.