Widget Script Error

Hi,

I have been running into an issue with my widget area. I have not installed the thickbox plugin yet I keep getting this error message:

A script on this page may be busy, or it may have stopped responding. You can stop the script now, open the script in the debugger, or let the script continue.

Script: http://sitename.com/wp-admin/load-scripts.php?c=0&load%5B%5D=jquery-core,jquery-migrate,utils,thickbox&ver=4.0:2

I’m wondering if the theme I’m using somehow has the plugin built in somewhere, I have confirmed that the plugin is not in my plugin folder.

Any thoughts? Thanks

https://wordpress.org/plugins/thickbox/