Same problem here, app down for several hours yesterday and so far about 3 hours today and still not working, just get 'Unknown error' message. Called support as a bit reluctant to take car anywhere at the moment after getting stranded in town with key fobs not working, app not working, car wouldn't unlock... eventually after increasingly wild clicking of fob got trunk unlocked and posted smallest child in who was able to dive over rear seats/ front console and somehow got the touchscreen to work and open the doors for the rest of the family. Why are computerised things so intuitive to the under 10s? Of course this was done in full view of a street full of people who thought it most amusing! Then of course it wouldn't start, just got a message that the car had to be unlocked before driving. More entertainment for the growing audience! More wild clicking followed and suddenly car burst into life, my kids were mortified, model X's are still quite a rarity in these here parts (north Scotland) so it still attracts attention just for being in town letalone breaking down in town! Anyway, support were really helpful, said this app/fob issue was across the board and laughed in an embarrassed 'yeah you got me' way when I queried whether Tesla had been hacked. Since I downloaded the last update this week my key fob hasn't worked properly though. Apparently there have been security issues across Europe regarding passive entry so that's been disabled, if you want to re-enable it just go through the settings menu on the control panel. I wondered whether it was the battery going, but haven't had any warning message, so tried the spare fob and had the same problem so thought it unlikely a co-incidence both batteries had gone when also the car was only serviced a couple of months ago and I understand they change the battery as a matter of routine anyway... My lesson learned though when I tried a few shops and found CR2354's aren't readily stocked here it would seem, so best to order a couple online to keep as spares. Anyway, support said everything was being done as quickly as they're able to rectify the problem, but meanwhile double clicking the roof of the key fob should at least unlock the car and get the fob recognised so you can drive the car again. Still it's quite a thought isn't it if it's affecting every Tesla across the world?....