Lync popups frequently to connect to address book.

Hi Team,

I have an issue with lync, which popups frequently to connect to address book and response groups.
Address book doesn't synchronize with the server.
The below is the Event log of that.

Address Book Server has encountered an unexpected exception.

Exception: The file cannot be accessed by the system.

Exception Type: System.IO.IOException

   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.Directory.InternalCreateDirectory(String fullPath, String path, DirectorySecurity dirSecurity)
   at System.IO.Directory.CreateDirectory(String path, DirectorySecurity directorySecurity)
   at Microsoft.Rtc.ABServer.ABServer.ReadContactsFromSqlAndWriteToOutput(NormalizeRuleSet normalizationRules, SqlConnection sqlConnection, List`1 sinks)
   at Microsoft.Rtc.ABServer.ABServer.Synchronize()
Cause: Internal Error
Resolution:
Contact Product Support Services.


Kind Regards,
Arun