Use wp_enqueue commands

[thomaspark]

Based on response from WordPress.org:

Your plugin is using <style> and/or <link> tags to insert CSS/JS

You should be using the built in functions for this:

https://codex.wordpress.org/Function_Reference/wp_enqueue_script https://codex.wordpress.org/Function_Reference/wp_enqueue_style

If you're trying to enqueue on the admin pages you'll want to use the admin enqueues

https://codex.wordpress.org/Plugin_API/Action_Reference/admin_enqueue_scripts https://codex.wordpress.org/Plugin_API/Action_Reference/admin_print_scripts https://codex.wordpress.org/Plugin_API/Action_Reference/admin_print_styles