on wikitext pages, I find the behaviour somewhat odd. The captcha doesn't get triggered until after i hit save (since it has to check if I am adding a link and am anon or unconfirmed). Then a captcha is displayed next to the save button along with a message "Your edit includes new external links. To protect the wiki against automated spam, we kindly ask you to enter the words that appear below in the box (more info):" while above the edit box at the top it tells me "Error
Incorrect or missing CAPTCHA." I didn't even get a chance to enter the captcha yet, so imho it shouldn't be warning me.
(also when I first saw "Incorrect or missing CAPTCHA", I thought it meant that the captchas were somehow not found on the server and didn't think it meant that the user didn't enter it yet)
and the message is "captcha-sendemail-fail" which just doesn't seem the right one to use here or is being abused / reused from something else? I don't see how this error has anything to do with email.
This appears to be caused by changes in the ConfirmEdit extension.