I did a new entry on my web site today. For some reason, when I look at the comment page, it says "Commenting is not available in this channel entry." And, no comment form shows up. I checked the entry options and "Allow Comments" is checked. Other entries on this site don't have this issue. Any idea why commenting is not allowed?
Figured this out. I checked the database, and this entry (in channel id 16) did have commenting turned on. But, there was another entry in a different channel (channel id 17) with an identical name/title, and it had commenting turned off. Somehow, EE got the two confused I guess. When I changed the name/title of the "other" entry (the one without commenting), then commenting on this entry started working.
Have you tried this one? "cmt_commenting_has_expired" => "Commenting is not available in this weblog entry.", I remember having the same problem at this website and it worked well. I hope it will help you.