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:
- Validate the password for the service account (RTCComponentService) used on the AppPool “LSGroupExpAppPool”
- Make sure the AppPool is started “LSGroupExpAppPool”
- Make sure the default website running the /Abs – application has a SSL certificate applied and that it’s responding on port 443 (https)
- 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”:
- Run: “abserver –regenUR” and wait 5 min.
- Run: “abserver –SyncNow” and wait 5 min.
A few references: