Hello,

Thank you so much purchasing our theme and contacting our support center.

This error means that you need to increase your upload limit in the server configuration. Here are some articles that describe it

http://www.wpbeginner.com/wp-tutorials/how-to-fix-are-you-sure-you-want-to-do-this-error-in-wordpress/
https://premium.wpmudev.org/blog/are-you-sure-you-want-to-do-this-error-wordpress/

Kind Regards
XTemos Studio