Fatal Error after updating plugins?

Here’s the message…

Fatal error: Call to undefined function w3_is_dbcluster() in /home/micha419/public_html/wp-content/db.php on line 30

Before I go into the host server, any ideas about what might have caused this? I was updating Toolset Types, Yoast and a couple other plugins – I now can’t access the dashboard or panels, however.

Here’s the code it references, starting at line 29:

$config = w3_instance(‘W3_Config’);
if ((!$is_installing && $config->get_boolean(‘dbcache.enabled’)) || w3_is_dbcluster()) {
if (defined(‘DB_TYPE’)) {
$db_driver_path = sprintf(’%s/Db/%s.php’, W3TC_LIB_W3_DIR, DB_TYPE);

        if (file_exists($db_driver_path)) {
            require_once $db_driver_path;
        } else {
            die(sprintf('<strong>W3 Total Cache Error:</strong> database driver doesn\'t exist: %s.', $db_driver_path));


Hello there,

I am sorry to hear the trouble you are having.

It seems like the trouble is coming from W3 Total Cache plugin. I have no clue about the reason why. Sorry :frowning: You should contact the plugin author who knows best about it. Temporarily, you could force disabling this plugin by doing the following steps, so that you could access your site dashboard again.

  1. Log into your file manager or FTP
  2. Navigate to root folder > wp-content > plugins
  3. Rename the “w3-total-cache” folder, e.g. “w3-total-cache-bak”
  4. Install and activate the fresh of W3 Total Cache plugin


Thanks, I’ll try that. The host (SiteGround) is trying to work it out, too. They’re pointing to the cache as the problem, too.

The site is entirely f***ed, as of the moment.

Yeah, I just deleted the plugin and the associated PHPs and will use my host’s cache features instead.

Thanks for the quick response!

Relevant topics in case anybody else faces the same issues: https://wordpress.org/support/plugin/w3-total-cache