Simple Fix When Windows 8 Lync App Cannot Connect to Server

By Ed Bratter
Posted in Infrastructure
On November 28, 2012

Now that Windows 8 is officially on the store shelves no doubt users will be scouring the Windows Store looking for Windows 8 applications to play with. One app users may find is the Lync application. Once installed, excited users will enter their credentials and expect to connect to Lync just as they do with their standard desktop client or Lync mobile client. Unfortunately, many users will be disappointed when they receive a “Cannot connect to server” error message. This will create a mad frenzy among users who claim they are entering the same credentials that they always use to connect. Lync administrators will be befuddled because they will successfully test an external connection with the desktop client going through the Edge Server and wonder why the new Windows 8 app won’t connect.

The solution to this problem has both good news and bad news. The good news is that the fix is easy (assuming you have correctly configured external Lync access through an Edge Server):  Simply install the CU5 (Cumulative Update 5) update on the Lync servers. The bad news is that this update may break mobility if it has been deployed.

Again, the fix is relatively simple. An update needs to be made to the web.config file located in the Microsoft Lync Server 2010\Web Components\Mcx\Ext folder:

  • Make a backup of the web.config file and then open it
  • Look for the following entry: Microsoft.Rtc.Mcx.McxService
  • Change the value so that it shows Microsoft.Rtc.Mcx.McxService2
  • Save the file

At this point both the Windows 8 Lync Client and mobility should be in working order.

Ed Bratter

Ed Bratter

Ed has over 15 years’ experience in the IT industry as a Systems Consultant, Systems Engineer, and Technology Specialist. He architects, designs, and manages Active Directory, Exchange, Citrix, VMware, and RSA SecurID solutions for Gotham’s clients, and provides technical expertise for Active Directory, Exchange, and Citrix.