WordPress has released version 4.9.4 just a day after 4.9.3 was rolled out.
WordPress 4.9.3 has addressed a number of bugs, but also introduced a new one, blocking users from running updates automatically. The error was discovered just hours following the release. Hence, WordPress 4.9.4 was announced immediately.
“This isn’t by choice – a bug went undetected during the 4.9.3 development cycle, and was only discovered hours after 4.9.3’s release. The bug causes a PHP Fatal error to be triggered when WordPress attempts to update itself,” WordPress explained.
How to update from 4.9.3 to 4.9.4 (as automatic updating won’t be working)
Log in to your WordPress Dashboard, go to Updates and click on the “Update Now” button.
Please note: if you’re running a version older than 4.9.3 there is nothing for you to do — you will be automatically be updated to version 4.9.4.
While this bug does not affect users, functionality or security, it’s best addressed sooner rather than later.