Issue with your code

Since 2.5.1 your code unconditionally loads a script on any admin call, see the end of
https://plugins.svn.wordpress.org/wpscreens/tags/2.5.2/admin/class-wp-screens-admin.php

This breaks any plugin that uses wp admin ajax as it ouputs that script on ajax responses.

Please use wp enqueue instead.

Also loading jquery from a cdn is against wp plugin guidelines so you should use enqueue with a jquery dependency

https://developer.wordpress.org/plugins/wordpress-org/detailed-plugin-guidelines/#13-plugins-must-use-wordpress-default-libraries

WordPress includes a number of useful libraries, such as jQuery, Atom Lib, SimplePie, PHPMailer, PHPass, and more. For security and stability reasons plugins may not include those libraries in their own code. Instead plugins must use the versions of those libraries packaged with WordPress.

https://developer.wordpress.org/plugins/wordpress-org/detailed-plugin-guidelines/#8-plugins-may-not-send-executable-code-via-third-party-systems

Calling third party CDNs for reasons other than font inclusions; all non-service related JavaScript and CSS must be included locally