jQuery validation plugin error: TypeError: validator is undefined

Question

Here is html code for the form:

Answer 1

Because this is the first topic that Google shows for "validator is undefined" then I will describe my solved problem, maybe someone will find it helpfull.

I was using 'maxlength' attribute (nothing fancy) and I got this error. The reason was nested forms. One of the textarea was inside both forms. Can happen when you have modals (dialogs) with forms in main view.