I am trying to comment on my own, active bounty, open question, here: Classify users by the pages they liked
and for some reason the page is not responding to my click on the "add comment" button.
I am using Firefox with windows 10.
I can't see anything about either the post or your account that would lead this to happen (unless you were doing it from a second account).
I do occasionally have temporary issues of a similar nature (with Firefox, and it has happened in both Windows 7 and 8) that are usually resolved by reloading the page, restarting the browser, or re-logging into the site. One time it didn't resolve until I restarted the computer.