Desktop UC client connection issues

[Microfiche]

Client version 6.0.56.0 running on Windows 10
Been working fine until this morning.
Checked certificates on the MAS server, all seems OK.
Have 2 clients out of 15 that can't connect this morning - both Win 10 Pro clients
Turned firewall off - no difference
Can ping and connect to MAS server over HTTP no problem from clients.
When I start the client, it looks like it connects and then immediately disconnects.
Then it just sits and cycles, trying to connect.
Any ideas? 

[Microfiche]

I think this is the error - though not sure what it means...

2016/06/17 11:00:28.651 INFO  [1:MainThread] Mitel.Communicator.Listeners.WebSocketListener - Setting the WSP socket state to Connecting because of connecting.
2016/06/17 11:00:28.672 ERROR [44:] Mitel.Communicator.Listeners.WebSocketListener - Web socket error:  System.Security.Authentication.AuthenticationExce ption: A call to SSPI failed, see inner exception. ---> System.ComponentModel.Win32Exception: The Local Security Authority cannot be contacted

Can anyone help? We have 3 Win 10 boxes running this, only having this problem recently on 2 of them.

[johnp]

Running that version on Widows 10 isn't supported. You can make it work using the correct dot net version. Not sure off the top of my head what version is required.

[sarond]

Please look at this post.
http://mitelforums.com/forum/index.php?topic=8562.msg37645#msg37645

KB2163017 and KB2163018 are the Winodws Updates you want to remove.

[rjp1977]

Hi

I've got the same issues but I don't have either updates installed. I've cant seem to find anything about that on ms.com either. Does anyone know if it's been superseded?

Thanks.

[Microfiche]

Thanks - that fixed it. I only had KB2163018 installed.
Had to download this ( https://support.microsoft.com/en-us/kb/3073930 ) from MS to hide it and stop from re-installing, because I just found out that this is no longer a standard feature in Win 10.
Honestly.

[Drew]

Can anyone confirm if the update doesn't effect version 7?
We have version 5.1 UCA and its done the same thing.
I've spoken with BT and they've informed me version 7 is available.  I'd rather not have to disable windows updates (will have to for now) but would be good to get confirmation version 7 is unaffected

[Microfiche]

Looks to me like it is affecting it...
http://answers.microsoft.com/en-us/insider/forum/insider_apps-insider_other/mitel-micollab-client-connection-error-and-windows/1d34ed16-e77a-4ad9-ba6a-f29d275389f7?auth=1

[sebiluke]

workaround...

It's working great for me..

 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\KeyExchangeAlgorithms\Diffie-Hellman]
 "ClientMinKeyBitLength"=dword:00000200

[Microfiche]

Looks like they are applying a similar update to Windows 7 now - almost all our UCA clients on Win7 started dropping connections this morning.
That same registry hack fixes it.

[tnstrauss]

how is the entry placed in the registry I have the default and I can't delete it I do know how to make a new entry... does the old need to go away??