
I've had this bug occasionally. This time it was on my alt, which does not have DLC.
One way it happened was being in a group with 3 other people, with 2 of them not having DLC, and it was only possible to queue when there were 3 or less people in the group, not 4. Perhaps the LFG function is only run if there are 3 in the group, and there is some kind of rogue value set prematurely instead of recalculating which dungeon should be searched for.
Either way, I'm pretty sure this is a bug.
Edited by VoidBiscuit on January 28, 2018 4:57PM