My campaign is falling apart because the PCs are too diverse and can't seem to find a common interest in anything. The only solution to this problem I can think of is a major crisis on a personal level.
Setting: Forgotten Realms
Campaign length: Two and a half years
Number of players: 6
Previous roleplaying experience: None to very little
Player types: 1 method actor, 1 powergamer, 1 storyteller, 1 social gamer, 2 specialists
Average character level: 13
Character alignments: 2x NG, 2x N, CN, LN