ummm, Kind of a big glitch.
Its not game crashing, you can just reload and your save file will still be there but here it is.
it is reproducible btw.
To get this glitch to happen, go to a save location, click up and while the "Saved" text is still a little transparent, click "Esc" everything will seem normal until you click "Continue" Then the game will freeze.
that's it, that game just freezes; no crash logs or anything. After a while google will tell you "This page is unresponsive" it's not, just reload the page.