Game crashed after “mouth full of boom”

I completed and got the achievement for “mouth full of boom” then the game crashed and lost a whole Act. I have to start over where the helicopter crashes.

Its the end you lie on your deathbed you last hear ¨A mouth full of boom¨ it all goes black then you see ¨You may now play as the cole train woo woo¨ as the rap slowly begins in the background
Nah but seriously idk mate