Maintenance for the week of March 16:
• PC/Mac: No maintenance – March 16
• ESO Store and Account System for maintenance – March 18, 6:00AM EDT (10:00 UTC) - 4:00PM EDT (20:00 UTC)
If you are trying to queue for random with someone who does not have the DLC and you have it, the queue won't work. Give the person without the DLC lead and let him queue, then it will work.