autocoach key missing?

[sohipsta]

Stucked in Underlands, found an emberian mask to feel good and emberian emulet too look good. But the most important item is missing, autocoach key!
To be honest my computer is barely alive, and often games crashes, maybe that's the issue. The autocoach key chest is opened, but i have no autocoach key in my inventory. Is there a way to reset that chest? or just to ctart whole game over againg