Microsoft have a page with links to all Lync downloadabels.

http://technet.microsoft.com/en-us/lync/dn146015.aspx

When you start the Lync Client and won’t get past “Contacting server..” ,and it never time’s out. It can be worth checking time on client and servers. Other users can sign in to Lync, even on the same PC. It will not help removing Lync client certificate, or reset password. Solution here is to check date and time on Lync server and Client – if it is Office365 it is your Client that has wrong time. 

You installed a update to your Lync 2013 server and wonder if the database has to be updataed (install-csdatabase….).

Run :

Test-CsDatabase -ConfiguredDatabases -SqlServerFqdn sqlserver.fq.dn | Select DatabaseName, ExpectedVersion, InstalledVersion

Result:
DatabaseName               ExpectedVersion            InstalledVersion
————               —————            —————-
rtcxds                     15.13.1                    15.13.1
rtcshared                  5.0.1                      5.0.1
rtcab                      62.42.2                    62.42.2
rgsconfig                  5.5.1                      5.5.1
rgsdyn                     2.2.1                      2.2.1
cpsdyn                     1.1.2                      1.1.2
xds                        10.13.2                    10.13.1
lis                        3.1.1                      3.1.1
As you can see there are a version conflict. You should update the database.

In this example the Central Management Database is not up to date. Check Microsoft TechNet KB 2809243 for the correct procedure: 

Install-CsDatabase -CentralManagementDatabase -SqlServerFqdn CMS.FQDN -SqlInstanceName DBInstanceName -Verbose

We defined a responsegroup workflow for anonymity. One user are a member of the Group (His Lync Client stated that for us.) When he select to call out as this queue he immediatly get the messeage that he is removed from the group.  On the monitoring server we get the message that he do not have permission – even when we are sure that he has.

We found out that this user has had his sip address changed some time. When we check the Lync sql instance “Rtc”, Database rgsconfig and table ado.Agents we found one entry with his old SIP address. Deleted this row from the table and ran a update-csuserdatabase. The new SIP address is imported into the database and now it works.

After you installed Lync 2013 on a Windows 2012 / Windows 2013 R2 Configuration management store will not replicate.

You think that it has something to do with the certificates but they seem ok. You will probably try to genereate new certificates to be sure, no… did’t help.

 The reason is the new way Windows 2012 handles the certificate store. For a technical description have a look at Technet article : http://technet.microsoft.com/en-us/library/hh831771.aspx .

If you just want things to start working add this registry key :

REG_DWORD “ClientAuthTrustMode” under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\Schannel and set it to value = 2 .

Or run this PowerShell command from an elevated PowerShell prompt:

New-ItemProperty -Path HKLM:\system\CurrentControlSet\Control\SecurityProviders\SCHANNEL

-Name ClientAuthTrustMode -Value 2 -PropertyType DWORD

The trust mode controls how validation of the client’s certificate chain is performed .

Contributed by Jan Helge Austbø

After installing Lync server 2013 persistant chat the service would not stay running.

Event Viewer entries complained about incorrect DB Version.

The reason for this is that I had installed a CU on the Lync server before I installed Persistent chat service.

Reran CU update and the service would start and stay running.