Elementalist: PERMA Mistform
This same bug happened to me again. I am level 80 now, was in WvW. This time I was already in Vapor form and moving when I rallied. When Vapor Form wore off I could not cast any spells. I died, could have saved myself if I could have used any skill.
regarding my original post, I used the word Mist form when I meant to describe the downed state skill “Vapor Form”