Processing the whole input

[xecdev]

We strongly recommend you never attempt to process the whole $_POST/$_REQUEST/$_GET stack. This makes your plugin slower as you're needlessly cycling through data you don't need. Instead, you should only be attempting to process the items within that are required for your plugin to function.

Example(s) from your plugin:
includes/class-paybutton-ajax.php:50 $raw_post_data = file_get_contents('php://input');