I know, manually transferring your files is a pain, so...
Activate Steam Cloud Saves!
Approaching Infinity uses a feature called "Steam Auto-Cloud" which syncs your save files when you close the game. This is now activated globally, for all users by default.
No other changes were made today.
There is a Known Psuedo-Issue with auto-cloud: sometimes it causes the Steam overlay to become unresponsive for a few seconds after closing the game. That is the nature of auto-cloud, because it does everything all at once. It doesn't mean there's anything wrong with Steam or your computer, and it's not something I can control, other than turning cloud saves back off for all users. So let's see how it goes, ok?
If you don't play on multiple machines, want to keep the data separate on purpose, or have another reason, you can always turn off cloud saves.
Here's how:
From your Steam library, go to settings, general, and then un-check the cloud box.
Wow, that's easy.
OK, enjoy, and we'll take a look at how it's going on Friday the 15th.