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Jabber clients 10.5.5 and 10.6 error Cannot communicate with the server


We've been using Cisco Jabber desktop client without any trouble for several months. Recently (past two days) I've had a couple of users with 10.5.5 client start seeing the error message "Cannot communicate with the server". This is using the default Jabber client configuration Makes no difference if the user is or isn't a UCM integrated user or if the user is or is not connected to our corporate VPN.

I've updated one of the clients to 10.6 but still see the same error. In the update, I first uninstalled 10.5.5 then installed 10.6.

Both clients are teleworkers using their home internet services but not seeing trouble with web browsing, e mail or VPN.

One client for a test logged into a Remote Desktop server here in office and was able to log into Jabber so it's not an account issue, no changes reported on either client PC.

For both clients as a temporary fix I've installed Cisco IP Communicator but I worry that having two of this error in one day, I'm probably going to see more of it soon. Also the users themselves are not happy with the CIPC.

Any suggestions on what to look for (No idea what server(s) Jabber uses by default) or what type of logs I can send to Cisco for them to review will be appreciated.


We had the same issue with a couple clients here.

We use WebEx Connect and automatic setup within Jabber.

It turns out that a certificate in the "Third-Party Root Certificates" called "QuoVadis Root CA 2" was missing.  When the client was connecting, the machine was rejecting the certificate.  We installed it manually and it solved the problem.

The bigger question is why wasn't the certificate being added automatically?  But that's something we'll look into later.


- John


Thanks so much! That fixed it for my first client today! Wonderful problem. What was really odd was that her phone was working one day then not the next so it appears that the certificate must have been present then gone. That aside, you saved my bacon on this one. Hopefully some day I can help someone else to pay it forward.


Thanks again!


Glad I could help!

Hi John,


Would you mind pointing me to where/which server this Cert lives on? Oddly, my lab has been running flawlessly for the past 3 months and just yesterday, jabber 10.6 via split tunnel VPN is throwing 'server communication errors'. LAN doesn't have that problem and it kinda 'smells' like ASA but zero changes have been made. I'm curious if I'm victim of the same QuoVadis???




Not sure where.  It was working fine on my machine, so I just exported it and copied over to the machine that wasn't working.  I can probably send it to you if that helps.


- John

Community Member

I had the same problem recently, but the cause was actually quite different. In my case it was a proxy issue - I had somehow managed to create some environment variables on my user profile for http_proxy and https_proxy, which Jabber used when trying to connect to the CUCM server. The proxy then disallowed this traffic and Jabber showed the "Cannot communicate with the server" message.

The csf-unified.log showed the following lines:

2015-09-18 12:21:30,510 INFO [0x00001384] [ls\src\http\BasicHttpClientImpl.cpp(410)] [csf.httpclient] [http::executeImpl] - *-----* HTTP response from: https://<my_cucm_machine>:8443/cucm-uds/version [18] -> 0.
2015-09-18 12:21:30,510 ERROR [0x00001384] [ls\src\http\BasicHttpClientImpl.cpp(414)] [csf.httpclient] [http::executeImpl] - There was an issue performing the call to curl_easy_perform: UNKNOWN_ERROR

I had curl installed on my (Windows) machine, so I was able to reproduce the issue by opening a bash shell and running 

curl -v https://<CUCM machine>:8443/cucm-uds/version

This showed the connect() attempt to the proxy server and returned an response of 'Received HTTP code 403 from proxy after CONNECT'.

You can check for this by looking in the HKEY_CURRENT_USER/Environment registry key, or by right-clicking My Computer->Properties, then Advanced system settings->Advanced tab->Environment Variables. (You can also run set from a command prompt, but that won't show whether it's user or system level.)

Deleting the http_proxy and https_proxy entries fixed up the issue for me.

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