Naturally, only the reviewers can tell why they rejected the edit.
However, I see a major problem which might have lead me to reject as well if I didn't take the time to click through to the original question:
You added the text of an error message that what never in the original question and that might or might not have been the one the OP really saw and which was also formualated and formatted in a way that it might be interpreted in way that you adressed the OP with it.
Yes, the error message came from a comment, but the reviewers don't see the commment section, only the edited question (*) so you should have at least left a better edit description than "copy editing"
(*) This is one of the reasons I don't review - the whole review system interface sucks and is just to much legwork to get the whole picture of what you are supposed to review...