I was just trying to join a group to do a heroic quest on Korriban. When the leader tried to invite me I got a message saying "You have conflicting instances with other members of the group. Reset your local phases." I have no idea what this is. Can anyone help me? It's annoying because I can't do any heroic quests right now. It's the Armed And Dangerous quest, if that matters.

It means that the planet has multiple phases because of population and you are in the wrong one.

 

Open your map and in the lower right corner there is a dropdown. Ask the leader what phase they want to work in and select that phase from the list.