The response data is missing from the ajax request error message
This issue occurs, when the plugin sends the search query to the server, but does not get back anything. In most cases it is only caused by a minor server misconfiguration, and should be possible to resolve by following a few steps.
Please note, that in most cases the cause of this reported issue is unrelated to the plugin. Therefore make sure to try the suggested resolutions below.

If you are using WP Rocket plugin

When the javascript defer feature is enabled, WP Rocket does a functional wrapping of inline script files. This sometimes causes an incorrect timing of the inline scripts used in the actual script files. Technical details here.
Please read their troubleshooting tutorial first here.
To the javascript defer exceptions list, please add the following:
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/ajax-search-pro/js/*
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Check if the empty server ajax handler is accessible

WordPress uses file within the wp-admin directory to handle all ajax related requests. When this file is not accessible, the issue occurs. Open up the following URL in your browser (replace yourdomain.com with your site address):
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yourdomain.com/wp-admin/admin-ajax.php
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The expected result should be exactly white screen with a 0 printed to it:
If you are seeing anything different - like a 404 page or anything else, that means this file is not accessible, and no ajax requests can be made. There are many reasons this could happen, we will list the most likely causes and possible resolutions.

Wrong redirections via the .htaccess file

The .htaccess file can be found within the root directory of your WordPress installation. It is mostly used by plugins and the WordPress system to resolve permalink structures. An incorrect rule can cause a wrong redirection, and make the ajax handler inaccesible.
    If you are using any plugins to change permalinks - SEO, Cache etc.. try turning those off first temporarily, and make sure those permalinks does not work anymore.
    Security/Firewall plugins tend to block requests to specific paths. Try turning off those plugins as well to test if the file is accessible.
    If you have added any custom .htaccess mod_rewrite rules in your .htaccess file, make sure to remove them - especiall if you are seeing a server error message (error 400, error 500 etc..) when accessing the wp-admin/admin-ajax.php file.
    If you have added any custom codes related to URL redirections or header modifications, make sure to remove them from the functions.php theme file (or from a custom code plugin if you are using any)
    Check your core WordPress permalink configuration. Try turning it back to the default configuration:
    If you are using WooCommerce, check the permalink configuration there as well.

Wrong redirections via plugin or custom code

    Make sure to temporary turn off any URL or page redirection plugins
    If you added any custom code anywhere in relation to redirecting URLs, make sure to remove them

wp-admin/ directory not accessible or moved to a different location

In some cases users tend to revoke access from the wp-admin/ WordPress directory. This is not only a very weak security measure, but conflicts with the correct function of the WordPress core.
If you still need to use a block on the wp-admin/ directory, make sure to add an exception to access the wp-admin/admin-ajax.php file, because it is important for not only this plugin, but the WordPress core (as well as any plugin/theme using ajax)

The server ajax handler works, now what?

Don't worry, there is still hope.

3rd party plugin conflicts

Some plugins (especially cache related) - when incorrectly configured - may conflict with the request headers, so WordPress does not know what to do with the request.
    Turn off any cache related plugins first. Then clear your browser cache and try again.
    Turn off CDN caching temporarily - Some CDN features can conflict with requests
    Turning off all the plugins one-by-one temporarily will also help pinpointing the conflicting asset
    Switching the theme is also a must, if everything else fails

Custom code

    If you have added any custom .htaccess mod_rewrite rules in your .htaccess file, make sure to remove them
    If you have added any custom codes related to URL redirections or header modifications, make sure to remove them from the functions.php theme file (or from a custom code plugin if you are using any)

None of the above works, now what?

As a last resort you can try the following option on the plugin back-end.
If none of the above works, feel free to open a support ticket with us.
Last modified 7mo ago