In reply to Pete Pozman:
Hi Pete, it's still Bing Maps but there's a problem with the Ordnance Survey layer. We're using version 6.3 of the Bing Maps API. It's scheduled to be discontinued on November 30, 2016 but they've obviously not included the OS layer in that roadmap
We've got to pretty much rewrite our code for the mapping from scratch since version 7 is so different and it's quite a big job. We'll endeavour to get it fixed ASAP.