The admin panel isn’t working.

Hello, we migrated our website from a domain.
Afterward, the WordPress admin panel started malfunctioning; we can’t activate the plugin’s license key.
The console is full of errors. The form where you need to activate the key isn’t responding at all.

The problem was with jQuery; some functions were…
Uncaught TypeError: o.widget is not a function.
We solved the problem, but with a bit of a hack.

like this
function load_custom_jquery_ui() {
if (is_admin()) {
wp_deregister_script(‘jquery-ui-core’);
wp_enqueue_script(
‘jquery-ui-core’,
‘https://code.jquery.com/ui/1.12.1/jquery-ui.min.js’,
array(‘jquery’),
‘1.12.1’,
true
);
}
}
add_action(‘admin_enqueue_scripts’, ‘load_custom_jquery_ui’);

Now, if you’re logged in as an admin, some jQuery functions don’t work on post pages, but if you’re not logged in, they work.

There are no errors in the admin panel.