I just upgraded to 4.21 from 3.34 (yes, I know I missed some old updates -- I'm trying to get on the ball now). I upgraded my templates so that commenting was provided by <$MTInclude module="Comments"$> and refreshed my templates to add in the comment templates (I think) I need. Pages build normally but now attempts at commenting fail with this error:

Comment Submission Error

Your comment submission failed for the following reasons:

Registration is required.

The commenter in question is registered with, and logged into, TypeKey. I don't see any way to log the user in or out. I don't want to require registration on my blog as well as with TypeKey. I'm still unfamiliar with 4.21 and am not sure where to look to turn this requirement off or to otherwise allow the user to comment. What should I do?