I've been using Lync 2013 in the last 12 months, and I love the product.

After applying KB2863908 some computers cannot log into Lync anymore. It gives the message "The server is temporarily unavailable..." This of course is a major problem.

I found  that I have this problem only for the computers (Windows 7 and Windows 8.1) that are not in the same domain as the Lync server. That is the computers that are in the domain they work fine as usual. The WORKGROUP and other domain computers have the problem.  Removing the patch fixes the problem, but I need a better solution.

Any ideas anyone?

Open the client logs in snooper and see if you can get a more detailed error message. To save time trawling, its best to exit Lync rename log file then open Lync, sign-in then check logs.

Info on client logs and snooper - http://www.lync.geek.nz/p/troubleshooting.html

04/06/2014|06:22:03.150 1234:1644 INFO  :: Data Received -***.***.***.***:443 (To Local Address: 10.***.***.***:60489) 690 bytes:

04/06/2014|06:22:03.150 1234:1644 INFO  ::

SIP/2.0 401 Unauthorized

ms-user-logon-data: RemoteUser

Date: Sun, 06 Apr 2014 12:22:03 GMT

WWW-Authenticate: NTLM realm="SIP Communications Service", targetname="***", version=4

WWW-Authenticate: TLS-DSK realm="SIP Communications Service", targetname="***", version=4, sts-uri="https://lyncweb.***:443/CertProv/CertProvisioningService.svc"

From: <sip:u1@***>;tag=774***28a;epid=1dd****4f7

To: <sip:u1@***>;tag=3C507E38399F***C4CE40E7EA4D42B

Call-ID: b84b1d7*****15591f9a3a21b18ecdf

CSeq: 1 REGISTER

Via: SIP/2.0/TLS 10.***.***.***:60489;received=***.***.***.***;ms-received-port=24525;ms-received-cid=307A00

Server: RTC/5.0

Content-Length: 0

04/06/2014|06:22:03.150 1234:1644 INFO  :: End of Data Received -***.***.***.***:443 (To Local Address: 10.***.***.***:60489) 690 bytes

Hi,

You can try to login Lync client manually instead of automatically.

The update may broke the user profile, please delete user profile with the following path:

%UserProfile%\AppData\Local\Microsoft\Office\15.0\Lync

It may also broke the root CA on the workgroup computers, so please double check the certificate.

Best Regards,

Eason Huang

I tried all this with no success.  I managed to get it going using the internal infrastructure. However, this is a temporary solution because it goes over the VPN, so we have double encryption (Lync + VPN.)