the plugin doesn't work, on multisite for "network plugin" activation

[tharlab]

is this project dead? I use this plugin, https://github.com/franz-josef-kaiser/WP-Plugin-Directories, the plugin doesn't work, on my multisite installation, for "network plugin" activation, but works fine on subsite. problem: when I click "network activate" from the network plugin, this error message appears ... "Plugin file does not exist."

my default config:

register_plugin_directory( array(
        'dir'   => 'dev-plugin',
        'label' => 'dev_plugin',
        'root'  => 'plugins',
    ) );

any suggestions will be appreciated

[franz-josef-kaiser]

About support: Well, the plugin was built 8 years ago as an answer to a WordPress StackExchange question. We improved it 7 years ago by adding an example plugin and minor stuff. So no, there's no official support for it. To be honest, I would not know if I would even use it with the raise of PHP Composer and wecodemore/WP Starter. Yes, WP is highly backwards compatible, so I'd assume that it should still work, while I have not tested it in years.

About your actual question:

• Prerequisites: You might want to turn on debugging both in your wp-config.php and on the actual PHP server.
• Option 1) Then you want to turn off all other plugins and switch to some default theme. It would be good if you could test it on a fresh (or better: fresh and local) install. Then turn on exactly one plugin –like Hello Dolly or something that does nothing than adding some string to some theme hook that you can look at– and see if the problem still persists. Then turn on one after another of your plugins and reload in between and see if it still works. Last, turn on your theme. Out of experience 80% of all problems can be solved this way as the reason mostly is developers ignoring how WP works and how paths and routes are resolved. In this case the conflict would be a different plugin.
• Option 2) If this doesn't work, start debugging this plugin. This is what I would do first, but it depends on how you feel with diving into the core of someone else code. The actual code for register_plugin_directory() is here. Internally this uses _get_new_plugin_directory_root( $root ). You can step by step debug in the plugin directly to see and compare where the plugin actually searches your plugins vs where your plugins actually are.

A last word: With the raise of Composer, which is a de facto standard these days, multisite installs imho only make sense if you want to build something like squarespace or wordpress.com. In any other case it's easier and faster to configure deployment via some continuous deployment service or our own cd server and push out websites and update them like this. Due to this fact multisite, even as core component, has a lot of annoying bugs and missing features that probably never will get resolved as the need is shrinking.

Best wishes!