Upgraded to WSUS3, now PC’s wont show. Help?

I upgraded my WSUS from 2.0 to 3.0 and now when I open into the council there are no pc’s shown. Nothing shows up, whereas before the upgrade all my pc’s were shown and updating fine.

I am trying to find the solution without have to wipe this and do a fresh install. Any help is greatly appreciated.

Thanks in advance.