wrote: thank you! But i dont seem to find that simcity folder anywhere.
And ive asked a friend on that region and he says he can't access it either (same alert). Does that mean its the servers fault?
If someone else is getting the same error message, then yes - the server side has the corruption, and there's really nothing anyone can do. I hate to say it, but your best bet is to just start a new region and mourn all the hard work you put in to the other one. 
It won't hurt to run the Origin fix tool anyway, just to clean up your cache and games. In the future, try not to exit and save directly after making a change - try to let the game run a little, just to give the data a chance to sync to the server before you exit. And playing with a wired connection can be better than wifi, just to limit chances of dropped connections.
I wish you great luck and happy building in the future!