For the last few weeks, when I try to connect to the marketplace I get the following message"

"We're unable to connect to the Marketplace Maybe Check your internet connection"

There is no problem at all with the internet connection and the iPad (and a heap of other devices) runs every other app and online service fine. This has also been tested on other WiFi networks, with the same result.

This has been happening for about 3 weeks. Today Minecraft updated, and all of our worlds are no longer there, in addition to the marketplace error.