We deeply apologize for that :(. There was an issue with the update that we released that wasn't dicsovered when we did internal testing.
Sadly the save file is lost and cannot be recovered, however, we will make good on our mistake.
Next week we will share a "master save" that will be downloadable for all affected users. This will contain everything that you could possibly want and hopefully rebuild your trust in us.
From all of us at Paradox we apologize for the problems caused with the patch and hope that you understand that this was by no means intentional.