Quote Originally Posted by MariaArvana View Post
It's not a bug, in certain cases.
When queueing for savage fights, you have multiple options to queue with. One of them is known as 'duty completion' or something to that effect, which can be toggled to check if everyone in the party has the fight uncleared, which will give the error message and let the party leader know if someone already has the fight cleared so you don't zone in by accident & clear the fight only to discover someone had already cleared it and the 2 chest you wanted was ruined. You can still go in if the party leader unchecks the 'duty completion' toggle though. But in OP's case, its likely the party was wanting 2-chest, meaning the error message was 100% intentional due to the party leader toggling the option.
I'm aware of how DF settings work but I can say with absolute certainty that it has still happened to me aswell as some others when I was party leader and set the settings in a way to allow for people with their weekly clear to join. Not often, but I've seen it a couple of times.
It was switched from "Duty Completion" (weekly lockout check) to Practice and we still got the error message a couple of times and it worked after trying again without changing anything. I don't know how else to explain it.
I'm not saying you're wrong with your assumption that it was probably intentional in this case if the party leader didn't allow for helpers, I'm just saying I have seen error messages even with proper DF settings.