I see this post:

www.limesurvey.org/forum/can-i-do-this-w...-characters-in-input

addresses how to set a minimum character length but I can't find this "advanced settings of question for Input"?

Where is that? I am trying to set the maximum character length for "other" in multiple choices.

As an aside, why does the button that states: "Add new question to group" keep popping up and as well, clicking on it does nothing. See attached screenshot of the annoying element.

Thank you.

This element makes total sense to be able to quicker add questions. However, currently this seems to be buggy. I have already created a bug report a couple of days ago. Today it has been asigned to someone:
bugs.limesurvey.org/view.php?id=14106

Regarding maximum characters: Please refer to the manual.
manual.limesurvey.org/Question_type_-_Lo..._.28maximum_chars.29

This is where you can set the maximum number of characters for a long text type question, which is the question type they are talking about in your link.

From what I understood, you are looking at something totally different. You want to limit the number of characters in the "other" text box.

What question type are you using?

Thank you!

It is the last entry for a list of multiple choice radio buttons. If you are going to send me to a file to edit, that's fine, but please tell me wherein the installation I would find that file.

Thank you.

As far as I can see, for this other field there is no option to limit the maximum characters. However, this is a small field, I doubt that anyone will insert a lot of text. Probably there is also a hard limit for characters on this small field or in the database anyway.

If you really need to limit the character number in this field you probably will have to do it via Javascript, but I have no idea how to do it.

I'm fine as long as there is a hard limit so that some malicious user doesn't pack the field with the encyclopedia Britannica.

I am quite sure there is a hard limit. If not imposed by Limesurvey, it is probably based on the type of Database column. So I don't think that you will receive the encyclopedia. You could make a small test. Just try to copy a huge text into the field and see what happens.