When I booted FS up today it indicated I was in Offline Mode with no Internet access. This wasn't true, of course, but FS has certainly had its share of servers going down or losing connection so I simply set the weather to match departure conditions as close as possible and took off. This meant I was without Live Weather, of course, and was also without regular ATC and Photogrammetry, etc. As I was approaching cruise it suddenly occurred to me that maybe FS had turned off my Internet connection and set me to Offline Mode without my permission (which it has certainly done on occasion).
I escaped into Options and quickly checked my Data and... sure enough, I had been set to Offline. I reset to Online and everything came back up. So, just a reminder to check your settings in Options when you get a "no Internet" message before taking flight.