Have you ever got this error? While this happens, you must make sure you have configured your wp-config.php. Check for these line:

define(‘DB_NAME’, ‘putyourdbnamehere’);

/** MySQL database username */
define(‘DB_USER’, ‘usernamehere’);

/** MySQL database password */
define(‘DB_PASSWORD’, ‘yourpasswordhere’);

/** MySQL hostname */
define(‘DB_HOST’, ‘localhost’);

Above is taken from wp-config-sample.php file. As long as you have configured the DB_NAME, DB_USER and DB_PASSWORD correctly, you should be fine. Some host might use a different DB_HOST, but mostly worked fine with localhost.

Well, if it does configured correctly and there still the same error happen, you might need to check the wp_options table.

Open the wp_options table using PHPMyAdmin or other similar software. Find the value siteurl in column option_name, if you see the option_value get a blank value like below:

Then you are probably on right track. Edit this row and insert your domain full URL in the option_value. Save.

Hopefully the error will go away. I don’t know why this could happen, but it did happen in one of my client website… It’s indeed frustating to look for this error, since WordPress didn’t give any specific information about it.

If you found another cause of this error, please share.