joints_register_sidebars not found or invalid function name

[enigmas213]

We have a site using joints_wp version 3.0. I know that this is an old version, but I'm reaching out in spite of that because we are in a pickle since we cannot upgrade to the latest version at this time.

Our error logs are blowing up with this error.

call_user_func_array() expects parameter 1 to be a valid callback, function 'joints_register_sidebars' not found or invalid function name in /var/www.supportuw.org/wp-includes/class-wp-hook.php.

What can we do to fix this error?

The version of wordpress we are using is 4.9.4.

The code in /assets/functions/sidebar.php is

`<?php
// SIDEBARS AND WIDGETIZED AREAS
function joints_register_sidebars() {
register_sidebar(array(
'id' => 'sidebar1',
'name' => __('Sidebar 1', 'jointswp'),
'description' => __('The first (primary) sidebar.', 'jointswp'),
'before_widget' => '

',
'after_widget' => '

',
'before_title' => '

',
'after_title' => '

',
));

register_sidebar(array(
	'id' => 'offcanvas',
	'name' => __('Offcanvas', 'jointswp'),
	'description' => __('The offcanvas sidebar.', 'jointswp'),
	'before_widget' => '<div id="%1$s" class="widget %2$s">',
	'after_widget' => '</div>',
	'before_title' => '<h4 class="widgettitle">',
	'after_title' => '</h4>',
));

/*
to add more sidebars or widgetized areas, just copy
and edit the above sidebar code. In order to call
your new sidebar just use the following code:

Just change the name to whatever your new
sidebar's id is, for example:

register_sidebar(array(
	'id' => 'sidebar2',
	'name' => __('Sidebar 2', 'jointswp'),
	'description' => __('The second (secondary) sidebar.', 'jointswp'),
	'before_widget' => '<div id="%1$s" class="widget %2$s">',
	'after_widget' => '</div>',
	'before_title' => '<h4 class="widgettitle">',
	'after_title' => '</h4>',
));

To call the sidebar in your template, you can just copy
the sidebar.php file and rename it to your sidebar's name.
So using the above example, it would be:
sidebar-sidebar2.php

*/

} // don't remove this bracket!`