Cannot Synchronize Address Book: Resolved
Like most of the users I too used to get “Cannot Synchronize Address Book” notification whenever i used to login in my OCS Communicator client. This happened when we do custom installation of any application, do not configure optional features etc.
I used to ignore that notification most of the time except today. I got irritated by yellow exclamation mark 
on Communicator Icon in system tray and I decided to hunt down the problem.
I didnt do much on my own except following paths shown by Google. I searched for a while, went through some forums and fixed the problem(s).
This post is to summarize the working steps gathered from different forums. Following are the steps that i followed in the process.
- Open the Office Communications Server 2007 management console and Expand server running with web components service.
- From the Available Task in right pane, Expand Validation and Select and complete the Web Components Server Validation wizard.
- If wizard failes with Connectivity error “Failure [0xC3FC200D] One or more errors were detected.” then problem is Default website on Web Component Server is not assigned with valid/no certificate. Refer here to fix this.
- If the Validation Wizard fails with GroupExpansion and AddressBookServer Configuration then the problem is because Windows Server 2003 SP1 includes a new security feature named loopback check functionality. Validation wizard tries to visit following URL’s but fails due to authentication failure. However, if you visit the same URL’s from system; other than Web Component Server, it works perfectly.
- https://[ocs_server_pool]/GroupExpansion/Int/service.asmx
- https://[ocs_server_pool]/Abs/Int/Handler/D-0ba0-0ba2.dabs
- Microsoft has already documented workarounds for these error. Follow the references and you are through.
- Once the problem is resolved you can search needed users contact details as shown in following screen shots. I am now happy to see my communicator free from Yellow Exclamation mark
