How do I view Address Leases on 2012 R2 DHCP server with red cross next to Address Leases ?

You mention a red cross.

Looks like a known issue. Here is a thread on 2003 to 2008 migration,
https://www.experts-exchange.com/questions/24789674/DHCP-server-can't-view-Address-Leases-red-x.html

And the MS link it references
http://support.microsoft.com/kb/962355

You might have reservations outside the scope. That's not allowed any more:
http://social.technet.microsoft.com/Forums/windowsserver/en-US/aaaaddbe-a8f2-41e9-87ab-be76a46b1df3/dhcp-leases-with-a-red-cross-and-event-log-errors

Thanks Carol,

The reservations were outside the scope and so I removed them. I unauthorised the server and then reauthorised but the red cross remains. I restarted the service but same result.

The MS article (962335) relates to how to export the DHCP database from the original server but this server is no longer available so unfortunately this is no longer an option.

In the social technet article the only possible procedure appears to be ..

1)deleted the scope
2)unauthorised the server
3)restarted the service
4)reauthorised the server
5)recreated the scope

Would you recommend this and is there a danger it would cause users disruption ?

Thanks