Hello,

Thank you so much for contacting our support center.

So if you can’t upload it via WordPress dashboard, then you need to increase uploading limits on your server. We suggest you to contact your providers for help in this situation.
Here is an article with detailed instructions about this error http://www.wpbeginner.com/wp-tutorials/how-to-fix-are-you-sure-you-want-to-do-this-error-in-wordpress/

A similar issue is also discussed here https://wordpress.org/support/topic/the-link-you-followed-has-expired/
But it is definitely not a PHP error.

Kind Regards
XTemos Studio