Hi Dingus_Khan, welcome to the forums. I’m sorry you lost all your stuff. There is a rare bug that can cause this to happen. We’ve got some changes coming next patch that should stabilize it more. It can happen if the game crashes right as a save is being made.
I probably can’t help restore it unfortunately. It should have attempted an auto repair when this happens.
The saves are stored locally on your own machine, we don’t keep saves on our server at the moment. When the game goes multiplayer, we will store saves on our servers.