I'm at my wits end.
I setup a whole new topology on a single Standard standalone Lync 2013 server on server 2016 (don't even ask me why still that old instacne and not a newer one, it's a sore subject that'll just trigger me).
I setup everything in a test environment and everything was working. We decided to test it with just a couple of us in IT, and sure enough the one thing I couldn't test (meet now with audio video, since it was all VMs without those hardware), doesn't work.
Yes, I have the latest May 2021 Lync CU installed.
Yes, I've done the Install-CSDatabase to resolve the issue after CU updates.
Yes, I've double checked all Simple URLs are correct.
Yes, I've run Enable-CSComputer.
2 Warnings: WARNING: No patterns found. Skipping rewrite rule creation for Web Scheduler.
Nothing related to meeting/conferencing
Yes, I've checked the Lync Control Panel and all Services are green.
Yes, I've Checked Event viewer, as how I cleaned up all other issues noted from CU update.
Yes, I've enabled verbose logging on the client. Main errors include:
"ERROR :: CRTCCccpDecoder::GetEndpointTypeFromText - unknown session-type:
WARN :: not expecting focus entity in getConference response
ERROR :: CUccOutgoingInviteOperation::Execute: HRESULT API failed: 80ee000b = hr. StartNegotiation on Media Flow failed
ERROR :: CUccPresenceDeviceInstance::ProcessValue - Timezone string is unexpected format (length 0, expected 14). Assuming timezone is GMT
ERROR :: SIP_URL::InternalInitialize Didn't find host while parsing SIP URL []"
The only one that seems relevant is the Media Flow one.
Yes, I've disabled the firewall on both server and client.
Yes, I created a dedicated open firewall rule on the Firewall between client and server.
Client is Skype For Business Office 2013, with all latest patches. 15.0.5233.1000
It makes me feel like a service issue on the FE side, but the logs are 100% clean there... I just can't figure it out! Driving me nuts! HELP!
NOTE 3 Symptoms are as follows: Click File -> Meet Now
New Chat Window pops up (if all appdata cache files are cleared) takes about 10 seconds before a prompt of how to connect audio appears (select Skype app to call in).
Chat Windows open with participants listed, and then "You have left the call" and a rejoin button.
If I click rejoin, rarely it will connect me in for about 10 seconds before again stating "You have left the call". Most of the time it simply goes right back to just "you have left the call"