Fatal error when updating from 21.8.1 to 21.9

[skinymikeofdoom]

• [ X] I've read and understood the contribution guidelines.
• [ X] I've searched for any related issues and avoided creating a duplicate issue.

Please give us a description of what happened

when updating wordpress-seo from version 21.8.1 to 21.9 a fatal error occurs: Fatal error: Uncaught Error: ftp_nlist(): Argument #1 ($ftp) must be of type FTP\Connection, null given

To Reproduce

Step-by-step reproduction instructions

1. Install wordpress-seo version 21.8.1 and activate the plugin
2. Update to 21.9 (using wp-cli or replace the plugin files manually)
3. refresh page

Expected results

1. Website should work

Actual results

1. Fatal error: Uncaught Error: ftp_nlist(): Argument #1 ($ftp) must be of type FTP\Connection, null given

Screenshots, screen recording, code snippet

If possible, please provide a screenshot, a screen recording or a code snippet which demonstrates the bug.

I think it is related to this section: https://github.com/Yoast/wordpress-seo/blob/13b47960d3b8371f9d380d6e44b750a3c8b48f31/wp-seo-main.php#L361

deactivating and then reactivating the plugin (using wp-cli) resolves the fatal error, it seem to be related to invalidating the cache.

Technical info

• If relevant, which editor is affected (or editors):
• [ ] Block Editor
• [ ] Gutenberg Editor
• [ ] Elementor Editor
• [ ] Classic Editor
• [ ] Other:

• Which browser is affected (or browsers):
• [ ] Chrome
• [ ] Firefox
• [ ] Safari
• [ ] Other:

Used versions

• Device you are using: Dell Vostro 5515
• Operating system: Windows 11/WSL Ubuntu 22.04.3
• PHP version: 8.1
• WordPress version: 6.4.2
• WordPress Theme: twentytwentyfour
• Yoast SEO version: 21.8.1 => 21.9 update
• Gutenberg plugin version:
• Elementor plugin version:
• Classic Editor plugin version:
• Relevant plugins in case of a bug: no other plugins installed

[enricobattocchi]

Hi @skinymikeofdoom, thanks for the report!

We'll investigate to find what happens.

[lunaluna]

@skinymikeofdoom @enricobattocchi

I had the exact same phenomenon. When I upgraded te Yoast SEO plugin from 21.8.1 to 21.9, I got a Fatal Error and the error was the same. The solution was also the same: deactivate the plugin using wp-cli and re-activate it using the same method.

Server architecture: Linux 4.14.165-131.185.amzn2.x86_64 x86_64 Web server: Apache/2.4.54 () OpenSSL/1.0.2k-fips PHP/8.0.25 PHP version: 8.0.25 (Supports 64bit values) PHP SAPI: apache2handler

[enricobattocchi]

@skinymikeofdoom @lunaluna We are try to reproduce it, can you tell us whether your setup requires you (or required just the first time) to insert your FTP credentials into WP to perform an update or a plugin installation via the GUI, as opposed to the "normal" case where it doesn't happen? Or is there any other relevant thing to know about your filesystem?

[skinymikeofdoom]

@enricobattocchi no ftp credentials are ever used in my configuration. I update the plugins using wp-cli for the most part - but I did test by replacing the files in situ and encountered the same problem.

It is also worth mentioning that I have reproduced this issue on 3 different server configurations (Docker, Rackspace and Azure)

[izzygld]

Getting same error/issue too.

Fatal error: Uncaught TypeError: ftp_nlist(): Argument #1 ($ftp) must be of type FTP\Connection, null given in /share/public/wp/wp-admin/includes/class-wp-filesystem-ftpext.php:438 Stack trace: #0 /share/public/wp/wp-admin/includes/class-wp-filesystem-ftpext.php(438): ftp_nlist() #1 /share/public/wp/wp-admin/includes/class-wp-filesystem-ftpext.php(456): WP_Filesystem_FTPext->exists() #2 /share/public/wp/wp-admin/includes/class-wp-filesystem-ftpext.php(757): WP_Filesystem_FTPext->is_file() #3 /share/public/wp/wp-admin/includes/file.php(2772): WP_Filesystem_FTPext->dirlist() #4 /share/public/content/plugins/wordpress-seo/wp-seo-main.php(361): wp_opcache_invalidate_directory() #5 /share/public/wp/wp-includes/class-wp-hook.php(324): wpseo_init() #6 /share/public/wp/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters() #7 /share/public/wp/wp-includes/plugin.php(517): WP_Hook->do_action() #8 /share/public/wp/wp-settings.php(506): do_action() #9 /share/public/wp-config.php(362): require_once('/share/public/w...') #10 /share/public/wp/wp-load.php(55): require_once('/share/public/w...') #11 /share/public/wp/wp-admin/admin.php(34): require_once('/share/public/w...') #12 /share/public/wp/wp-admin/index.php(10): require_once('/share/public/w...') #13 {main} thrown in /share/public/wp/wp-admin/includes/class-wp-filesystem-ftpext.php on line 438

[enricobattocchi]

Hi everyone, thanks for the info. We are going to release a new version today that (among other stuff) should fix this issue by reverting the change that introduced the problem. We will look into improving our solution making sure that it doesn't cause similar problems.

[enricobattocchi]

The release is out, fixing the issue. Thanks everyone of your info and for your patience.