Only a day after Wordpress 4.9.3 was released, it released 4.9.4 version to fix a critical bug that broke the automatic update mechanism in Wordpress.
Last week, Wordpress released a 4.9.3 version with patches for a total of 34 vulnerabilities. But unfortunately, a bug went unnoticed during the 4.9.3 development cycle which triggers a PHP Fatal error when WordPress tries to update itself automatically.
Explaining about the bug WordPress lead developer Dion Hulse said:
“#43103-core aimed to reduce the number of API calls which get made when the auto-update cron task is run. Unfortunately, due to human error, the final commit didn’t have the intended effect and instead triggers a fatal error as not all of the dependencies of find_core_auto_update() are met. For whatever reason, the fatal error was not discovered before 4.9.3’s release—it was a few hours after release when discovered.”
However, a few hours after the 4.9.3 version release, the Wordpress team discovered the bug and issued a fix in the Wordpress 4.9.4 version.
But the Wordpress s who have the 4.9.3 version need to manually install the 4.9.4 version update by themselves for now.
There are several ways in order to manually install the update.
- Wordpress s can sign into their s, Dashboard→Updates and then click “Update Now”.
- Through command line, use the ‘wp core update’ command to get the update ( if WordPress and WP-CLI installed previously).
- To manually install the update by FTP, the latest ZIP and it to your site using FTP. Only the
wp-includes/update.php&wp-includes/version.phpfiles are expected to change.
Make sure you have the WordPress 4.9.4 version after the installation.
However, it seems that the bug was limited to only a few websites, as few s found both the updates (4.9.3 and 4.9.4) automatically installed.
Share your experience in the comments if you had to manually install the fix.
