When running The Lync Server 2013 cmdlet Test-CsExStorageConnectivity to test connectivity to Exchange 2013, you might see the error Access Denied as shown below
Test-CsExStorageConnectivity : ExCreateItem exchange operation failed, code=5,
The reason could be that the user running the cmdlet is not member of the local group "RTC Local User Administrators". Membership of the domain group RTCUniversalUserAdmins will automatically give you membership of the needed local group.
Use whoami /groups in a command window to see your group membership.