Possible Duplicate:
New rule preventing multiple @notifies causing Convert to Comment to fail
As a moderator, I am trying to turn this answer into a comment. The answer starts with “@chris @vebjorn”. I get the following (full-page) error message:
Only one additional @user can be notified; the post owner will always be notified
I think this check should only be applied when a user is posting, not when a moderator is converting an existing post.
I worked around the problem by editing the answer before converting it into a comment.