How to solve an error in the console due to which some pages of the site are displayed incorrectly?

Question

JavaScript

Good afternoon! Some pages of the site are not displayed correctly. I saw the following error in the console:

Uncaught TypeError: $(...).mmenu is not a function
    at HTMLDocument.<anonymous> ((index):2871)
    at j (page_2e12b2169d57c6dffd180836f5333c77.js?1550378488151578:93)
    at Object.fireWith [as resolveWith] (page_2e12b2169d57c6dffd180836f5333c77.js?1550378488151578:93)
    at Function.ready (page_2e12b2169d57c6dffd180836f5333c77.js?1550378488151578:93)
    at HTMLDocument.J (page_2e12b2169d57c6dffd180836f5333c77.js?1550378488151578:93)
(anonymous) @ (index):2871
j @ page_2e12b2169d57c6dffd180836f5333c77.js?1550378488151578:93
fireWith @ page_2e12b2169d57c6dffd180836f5333c77.js?1550378488151578:93
ready @ page_2e12b2169d57c6dffd180836f5333c77.js?1550378488151578:93
J @ page_2e12b2169d57c6dffd180836f5333c77.js?1550378488151578:93

How can it be corrected? I don't know js at all. I've been sitting for two days now.

Answer 1

The mistake was that the site used to have a module for the content manager. The module loaded its JS. deleted the load and everything was OK

Answer 2

Surely there should be mmenu and not menu , or someone mistyped?

Answer 3

Most likely the plugin is called before it is connected. Move the connection above:
head
script src="path/to/jquery.js"
script src="path/to/jquery.mmenu.js"
link href="path/to/jquery.mmenu.css" rel="stylesheet"