How can I open a backup or autosaved with unreal turned off?

Hey folks! Unreal crashed and I can’t open again a finished project. Program crashes everytime I try to open it. I can open another works without problem.
I recibe the following message: “Assertion failed: InPoss <= Size File: \Build++UE4\Sync\Engine\Source\Runtime…”

I hope you can help me.

Thanks!