Unable to download the Address Book

Author: Rob Pittfield

Publication date: October 2008

Product version: Office Communications Server 2007 R2

A common issue we see is clients getting an error stating “Cannot Synchronize Address Book”. It looks like this:

There are several reasons clients could get this error. One possible reason is the TLS Certificate hasn’t been selected yet in IIS on your OCS 2007 Front End Server (in a Standard Edition Deployment) or on your Web Components Server (in an Enterprise Edition Deployment).

To see if this is the cause, do the following:

  • Open the Internet Information Services (IIS) Manager from Administrative Tools.
  • Expand the Computer and then Web Sites.
  • Right click on Default Website and then click on Properties.

In the Properties box that comes up (shown below), check to see if the SSL port information is blank. If it is, then you likely haven’t installed the certificate required for SSL yet.


This is an action that the OCS installation doesn’t take care of automatically so it happens pretty regularly. To resolve it, select the Directory Security tab and click on the Server Certificate Button:

After you click on the Server Certificate button, follow the Wizard, select Assign an Existing Certificate and assign the certificate used by your OCS Server for client logins. Once you’ve assigned the certificate the SSL port on the Web Site tab should be filled in with port 443.

Sign your clients out of Communicator and then back in and the Address Book should be downloaded successfully.

There are several other reasons this download could fail, and we’re going to try to address them in more posts coming in the future.

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