So, what do you do when two players (not characters) clash, and don't play together well?
Can a game be saved from this situation?
Not easily, no. Most table-top RPGs are much more a team activity than a simple group activity, and no team in any context works well when team members can't put personal differences aside.
If you absolutely have to work past it, your best option, I'd guess, is to recast your game as a non-team activity -- or, at the least, put the players with differences on different teams. Honestly, though, I can't see it coming to any good end. It all comes back to Rule #1: you game for fun. If you have to game with someone you dislike, it stops being as much fun.