The game had a CTD last night. I loaded my game today and I was at a point 2 or more hours before the crash. I had completed a quarantine zone so it should have saved after that I would think or after any of the other 3 or four quests I completed.
I played for a few minutes and then quite the game. I reloaded and I was again, back where I had been before. The game is no longer saving my progress. The last save was right after I opened a drop container that was empty. It stopped saving after that. It stopped saving right after I saw the plane deliver the two drops. I also have a quest to deliver the goods from the first drop to the quartermaster, but the drop box was empty, so there is nothing to deliver. I think it must be a major game glitch. Too bad I don't have other saves to go back to. Two days of game play wasted.
Anyone know what's up? Or was this just a waste of money. Luckily it was on sale.

Looks like there are different versions of the game mentioned here. I have the Dying Light: The Following - Enhanced Edition.

I don't know how to solve your specific problem.

But the game does have a feature where you can restart the game from a previous quest that you have already completed...but I believe you lose your side quests progress if you do that.

That's still not ideal, but doing that might be a sort-of workaround to your problem.