Imaculata
Hero
The times I've had a table disintegrate under me is when I had an argumentative player that couldn't accept the consequences of their actions, and when PvP entered the game. That causes enough strife and hard feelings that the players leave and go their own ways.
I've left a game where the DM allowed another player to kill my character. It didn't help that the DM allowed my character to miraculously survive the assassination, because how did he expect our two characters to ever work together again? That is not a minor disagreement that you can just sweep under the rug and pretend it never happened.
This is why I establish a clear "no-pvp" rule during the session 0 of any campaign I run. Any player that objects to that, is welcome to leave my table.