Additional Instances Cannot Be Launched

Hey, trying to run some DM jump runs on my shaman and after running twice I’m getting this error. Help?

Same here…trying to run SM Armory on my warrior…can’t get in. Brought my mage up who hasn’t run ANY dungeons in 3 days, same thing.

Hearing people are saying its because a lot of people are inside instances, namely bots. Not sure if there is any truth to this.