Post preview & customizer not working JS error

Site is https://www.girlontheriver.com/

I have done the following to check why the post preview function and theme customizer aren’t working.

-deactivated plugins
-changed theme to standard
-updated premalinks
-checked site URL’s match in settings

I have done a javascript test on the theme customizer page and got this:

Uncaught ReferenceError: addLoadEvent is not defined
at customize.php?return=%2Fwp-admin%2Fthemes.php%3Factivated%3Dtrue:1454
https://www.girlontheriver.com/?customize_changeset_uuid=9423631e-72f1-414b-…3a43e09d&customize_theme=DiviChild+2&customize_messenger_channel=preview-0 Failed to load resource: the server responded with a status of 500 (Internal Server Error)
jquery-migrate.min.js?ver=1.4.1:2 JQMIGRATE: Migrate is installed, version 1.4.1
scripts.js?ver=1.0:23 Uncaught TypeError: Cannot read property ‘search’ of undefined
at HTMLDocument.<anonymous> (scripts.js?ver=1.0:23)
at HTMLDocument.dispatch (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,underscore,wp-util,jquery-ui-core,jquery-ui-…:3)
at HTMLDocument.r.handle (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,underscore,wp-util,jquery-ui-core,jquery-ui-…:3)
at Object.trigger (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,underscore,wp-util,jquery-ui-core,jquery-ui-…:3)
at Object.a.event.trigger (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,underscore,wp-util,jquery-ui-core,jquery-ui-…:9)
at y (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,underscore,wp-util,jquery-ui-core,jquery-ui-…:4)
at XMLHttpRequest.c (load-scripts.php?c=0&load[]=jquery-core,jquery-migrate,underscore,wp-util,jquery-ui-core,jquery-ui-…:4)
jquery-migrate.min.js?ver=1.4.1:2 JQMIGRATE: Migrate is installed, version 1.4.1
https://www.girlontheriver.com/?customize_changeset_uuid=9423631e-72f1-414b-…3a43e09d&customize_theme=DiviChild+2&customize_messenger_channel=preview-0 Failed to load resource: the server responded with a status of 500 (Internal Server Error)
/wp-includes/js/jquery/jquery-migrate.min.js?ver=1.4.1:2 JQMIGRATE: Migrate is installed, version 1.4.1