Order admin detail page is blank

I have just updated to 3.0.0.7 on my multisite installation in the live environment. When I go in to the admin page for orders I can not see a full list of past orders. When I click on the order id to edit the status, add notes, see the details etc. - The page goes blank - white screen. Not good!

Please help me fix this so that my stores can see their orders to process them.