Yoast SEO WordPress plugin version 19.7 was discovered to contain a conflict with other plugins, resulting in websites experiencing fatal errors.
This marks the third instance this year where a conflict with another plugin caused a Yoast update to fail.
Fortunately, Yoast investigated the reports and swiftly published a new update to rectify the issue.
WordPress Fatal Error
There are various causes for a fatal error, but in this situation, it was due to an update to Yoast SEO conflicting with another plugin.
This can occur when two plugins attempt similar functions, leading to one canceling out the other or otherwise preventing each other from functioning.
A metaphor for a plugin conflict could be two cars going in opposite directions on a one-lane road.
Ideally, plugin developers make allowances in their coding for other plugins, especially common ones, to ensure smooth functionality. This was the exact issue with the Yoast 19.7 update.
Yoast 19.7 conflicted with other plugins (or custom coding) that change the admin login URL. Changing the login URL is a security measure designed to thwart hacker software that automatically navigate to the default URL for administrator logins to guess the login credentials.
Yoast Announces Update Bug
Yoast was fully transparent about the bug and informed users through a tweet describing the situation:
“After the release of Yoast SEO 19.7, we were informed that this version causes a fatal error when used in combination with plugins or code that alters the default WordPress login URL. We’ve identified the problem and are working on a solution.”
One of the changes in Yoast 19.7, according to the Yoast plugin development changelog, was an improvement in handling fatal errors by preventing Yoast from running on the login page:
“Improves the handling of fatal errors in the front-end by preventing Yoast SEO to run in the login page, allowing users to access their dashboard.”
Could that have been the cause?
Why Do Fatal Errors Happen With Plugins?
Plugin conflicts are not exclusive to Yoast. It’s simply more noticeable when it happens to Yoast due to their large user base. However, this is the third instance this year of a fatal error due to a Yoast plugin update.
Yoast SEO Plugin founder Joost De Valk explained in a tweet that it’s not always possible to account for the thousands of plugins in the WordPress ecosystem which could potentially conflict:
“This is the sort of #WordPress plugin conflict situation that I literally don’t know how to prevent from happening. 60,000+ plugins: how do you test your plugin against all of those? If someone has good ideas, I’m all ears.”
Joost also mentioned that Yoast always tests their plugin updates with many of the most popular plugins before release:
“We test against the big ones, not worried about those as much, but a couple small ones together still cause enough of a headache.”
"…it’s never fun when you break stuff. We test very rigorously and still stuff goes through. Building plugins for large amounts of users is “just” hard.”
Solution Offered Within Hours
Yoast published a new update within two hours of announcing that they identified a bug and were working on a solution.
They tweeted: "We’ve resolved the problem and released a patch. You can now safely update to Yoast SEO 19.7.1. We’ve marked the incident report as resolved."
Recommended Action To Take
Yoast released a new update, version 19.7.1. The Yoast development changelog stated:
“Fixes a bug where a fatal error would be thrown in combination with certain plugins that change the standard login page URL.”
Users of the Yoast SEO plugin should consider updating to the latest version, 19.7.1.
Featured image by Shutterstock/Asier Romero
