How to Fix Fatal Error After Installing SiteOrigin Page Builder

Today, a user told Naiba that his WordPress website was inaccessible and asked for help. Opening his website showed the error: „Fatal error: Call to undefined function wp_doing_ajax() in /home/vgr8rn8v8/wwwroot/wp-content/plugins/siteorigin-panels/siteorigin-panels.php on line 45"

Cause of the Problem

Judging from the error message, the problem lies with the wp_doing_ajax() function file. The wp_doing_ajax() function was added in WordPress 4.7 and later, and this user happened to be using an older version of WordPress. For reference, you can check the official documentation:https://developer.wordpress.org/reference/functions/wp_doing_ajax/wp_doing_ajax() is used to determine if the current request is an Ajax request. It returns true for WordPress Ajax requests, otherwise false.

function wp_doing_ajax() {
    /**
     * Filters whether the current request is a WordPress Ajax request.
     *
     * @since 4.7.0
     *
     * @param bool $wp_doing_ajax Whether the current request is a WordPress Ajax request.
     */
    return apply_filters( 'wp_doing_ajax', defined( 'DOING_AJAX' ) && DOING_AJAX );
}

Solution

From the error message, it's clear the problem is on line 45 of siteorigin-panels/siteorigin-panels.php. The issue is plugin compatibility. The solution is simple: use an FTP tool to connect to your website server and delete the 'siteorigin-panels' folder. If you still want to use this plugin, you need to first upgrade WordPress to a newer version and then reinstall it. If you cannot upgrade, you should check if your server environment meets the hardware requirements for the newer WordPress version.WordPress Configuration Requirements Hardware conditions required for installing WordPress

Other situations

Sometimes, a website becoming inaccessible might not be due to a plugin issue. Naiba previously shared the Ultimate Troubleshooting Guide for WordPress 503 Errors. Those interested can read it.

Ultimate Troubleshooting Guide for WordPress 503 Errors