I've played with friends and am encountering a game breaking bug with legendary "Operation: Seraph Station" that seems to only occur when they play regardless of whether they are by themselves or with others that is preventing them from getting all of the catalysts for Revision Zero. What fails to occur is a vandal in a room with three turrets fails to drop a buff that comes in the form of a prism that one player would pick up and then a servitor would spawn that after you defeated and you would then get the controller buff from the console in the room, the servitor does not spawn however without the drop and you cannot access the console and get the controller buff as a result (this occurs shortly after the room with the secret chest behind the lasers). Several bugs that consistently occur shortly before the event are when you first encounter the cursed thrall the knights do not spawn with them and the shriekers are not present in the room after. Note that this bug has occurred before on the legendary version when we were doing a group of three but we were able to start the mission over and it would not occur after one or two attempts (did not seem to be an issue period with less than three). However it is occurring consistently whenever these friends play where it is impossible for them to proceed in a group or by themselves. A difference with them is that they did not do each catalyst quest the week the quest was first available but later, I have suggested discarding the later catalyst quests to see if it has impact but they did not wish to do so. (An additional bug that occasionally occurs independent of this on this mission a is the ability to crouch is sometimes lost by one or two players, preventing things such as warlock rifts from being possible and requiring one player to handle all the vent sections)