HTML5 app cache
On my Nexus 7 today, I got this message from the FT app: FT could not be opened because it is not connected to the Internet. This is an odd error message.
The best way to fix this? Clear the cache in Android (just for the application). Or you can Force Stop the application afterwards and it should restart just fine.
Why? There are issues with HTML5 app cache. Some resources: Debugging HTML5 Offline Application Cache, Fixing app cache from the FT themselves, and some sensible comments at Stack Overflow.