It is a humungous bug that the new doubleclick studio has.
What happens is that the new component for some reason alters the linkage to the doublelick classes. So, right now it looks inside the AS2 version of the files instead of the AS3 (This part is just a theory because we still dont know what causes the error for sure. But we do know is linkage related).

The only fix that that I found is to delete the AS3 document classes from the preferences in flash. I know its crazy, but if you really need to make it work that will do.

Also, this happened to me when I installed the Pointroll API. Not sure if that is your case.