I was in a Rio CTF battle that wouldn't end (each team had 2,000+ kills, 200,000+ fund), then it started to say I was inactive, even though I was still moving around. All the other tanks stopped (similar to what would happen if you are lagging). After a minute or two, everyone self-destructed, I wouldn't respawn, it said I was inactive, and then the "an unexpected error has occurred" screen appeared. I am not sure if this has anything to do with the battle never ending or if it was something else. Also, this happened to me in a Kunger CTF (a regular battle), but it didn't say I was inactive.
My internet is perfectly fine and does not normally act unusual. I then clicked restart, which sent me back to the home screen of the game.
Customer support service by UserEcho