Address book is not updating in Lync Application.

 I have updated the address book in server using  Update-CsAddressBook command and it was success but it is not updating on users machine, i have done the registry entry.

reg add HKLM\Software\Policies\Microsoft\Communicator /v GalDownloadInitialDelay /t REG_DWORD /d 0 /f

But still it is not working giving below error.

cannot synchronize with the corporate address book. this may be because the proxy server settings in your web browser does not allow the access address book. if problem continues, please contact your support team.

Kashi