One of my answers got some comments, and some of the commenters and me were having an exchange of ideas.
I (and some commenters) realized that it should be moved to chat, so I did click on the link.
The issue is that I returned to the question and, while trying to do some cleanup, accidentally deleted the (automatically generated) comment that linked to the chat room. Now the chat room is unreachable (if it still exists at all) and I no longer have the option to create a new chat room.
I think the comment with the link to the chat room should not be deletable.