I open my project and I found that everything's gone?!

I was opening my project on unity and I find everything that i’ve put in the scene is gone.even all of the scenes are gone.All I find is the main camera and the assets that i’ve got.Please help me.I save before I close anything.

There’s no way to get it back.

In the future, save a backup copy of your entire project folder at least once a day onto Dropbox. That way, when this sort of thing happens, you will never lose more than one day’s worth of work.

You can rage at Unity over this; but the truth is, if you weren’t making backups you were asking for it, and often it takes this kind of experience before you really learn. You should just assume that at some point your project will become irreparably corrupted, and plan ahead so that when it happens, it’s a temporary annoyance instead of a catastrophe. Just like you should expect that some point in your life you will lock your keys in your car, and get a duplicate car key made before that happens, etc.

This happens when you open the project in an older version of Unity than before, if you open it up with the most advanced version of Unity it should all be there.