The install itself went smoothly. I am now suffering the following issues - - Three times since the upgrade (1 week ago), all hard phones have lost audio when receiving/sending an external call. The fix is to restart services or run firewall check (which restarts services) Firewall checker passes with no errors. Internal calls never fail - Soft phone issue - The soft phone CTI mode will not connect to the hard phone and you cannot view call history/contacts/presence info in any mode. This can be fixed with resending the welcome email and reinstalling but I'm trying to avoid that. Strangely, 3 out of the 30 connected softphones have not lost any connectivity and continue to work. - Android and MAC mobile installs all stopped working but work after a reinstall - Error in log - 3cx error block WAN requests is on - But I cannot be sure that this event occurred at the same time as the outages Side info - Server is installed in Windows 2012 R2, a handful of patches were applied at the same time as the upgrade. Desktops are all Windows 10 I have a feeling during install I may have selected to address phones by FQDN rather than IP but only a hunch. Would that cause these issues? Thoughts?