Communicator 2007 – cannot synchronize address book

When this error is seen in the Communicator 2007 and Communicator 2007 R2 client, it can be a number of issues.

Here’s a few steps to check:

  1. Validate the password for the service account (RTCComponentService) used on the AppPool “LSGroupExpAppPool”
  2. Make sure the AppPool is started “LSGroupExpAppPool”
  3. Make sure the default website running the /Abs – application has a SSL certificate applied and that it’s responding on port 443 (https)
  4. Shut down and restart the Communicator 2007 (R2) client

These steps helped for me, when seeing the failure “Cannot synchronize address book” on all Communicator 2007 clients.

Address Book regeneration:

In case the Address Book needs to be regenerated, it can be done using these steps:

From the OCS folder: “C:Program FilesMicrosoft Office Communications Server 2007ServerCore”:

  1. Run: “abserver –regenUR” and wait 5 min.
  2. Run: “abserver –SyncNow” and wait 5 min.

A few references: