I just found out yesterday that people couldn’t comment on my site at all. I did, in fact, have the default post setting to allow comments. However, through a search here on the support site, I found an item that solved my issue.
In the INDEX.PHP file, near the top, but after the < HEAD > tag, is a line that is commented out that has to do with comments. Simply removing the two slashes — // — then saving the file and reloading it my browser proved to be all that I needed. The comment pop-up box came to life!
If the comment pop-up is the only way to allow comments (and I don’t know this to be true) then why is it not “allowed” i.e. not commented out, by default?
Anyway, I hope this helps!
Craig.