The value of the MSRTCSIP-Line URI field in your local Active Directory conflicts with another user. %BRAND_LYNC_ONLINE_SHORT% ...

The value of the MSRTCSIP-Line URI field in your local Active Directory conflicts with another user. %BRAND_LYNC_ONLINE_SHORT% features will work except for Lync-to-phone calls. To resolve the conflict, correct the value in your local Active Directory. After you correct the value, the value will be updated in your %BRAND_OFFICE_365_SHORT% directory during the next Active Directory synchronization. If the error persists, please contact %BRAND_COMPANY_SHORT% support for assistance.