Re: Cannot melee on the final mission.

@streaksrm I've seen videos where she can be finished off with gunfire, and I don't recall needing to melee her myself. Nevertheless this doesn't really address the issue. 

Generally if the game is "weird" and the issue persists, the saved gamestate has gotten a little odd. The usual way around this is to load into the game from the Mission Select option at the start page. 

This should give a "clean" version of the level, and you should hopefully not have any further issues. 

Thanks.