Fatal error regarding wp_generate_password() in any version past 4.1.3

Hi. Thanks for creating and maintaining this plugin, as well as providing support for it.

We are experiencing an error on any version past 4.1.3 version (I did not test every version — just 4.2.2, 4.2.1, 4.1.9 — so it may occur at some point between 4.1.9 and 4.1.3).

The error only occurs on certain environments. E.g., we use a local Docker container and the plugin is fine there. However, once pushing to the live preview service Tugboat — we receive a critical error. Logs attached below.

This is not unique to our situation as it is the same issue as described in this support thread.

The error has something to do with the WP filesystem used. Similar error from a different plugin, explanation by that plugin’s author:

Looks like you’re using “ftpext” WP filesystem method instead of default “direct” method, and not configured it. This is why you’re getting this error. As of 2.2.5, you’ll get an admin error notice which says “Your WordPress filesystem method “ftpext” is not configured correctly. Please configure it, or use another method like “direct” to be able to continue using the plugin.”

Error log:

Fatal error: Uncaught Error: Call to undefined function wp_generate_password() in /var/lib/tugboat/wp-admin/includes/file.php:678 Stack trace: #0 /var/lib/tugboat/wp-admin/includes/class-wp-filesystem-ftpext.php(138): wp_tempnam('/var/lib/tugboa...') #1 /var/lib/tugboat/wp-content/plugins/responsive-menu/v4.0.0/inc/classes/class-theme-manager.php(436): WP_Filesystem_FTPext->get_contents('/var/lib/tugboa...') #2 /var/lib/tugboat/wp-content/plugins/responsive-menu/v4.0.0/inc/classes/class-theme-manager.php(850): RMP\Features\Inc\Theme_Manager->get_themes_from_uploads() #3 /var/lib/tugboat/wp-content/plugins/responsive-menu/responsive-menu.php(170): RMP\Features\Inc\Theme_Manager->get_menu_active_themes() #4 /var/lib/tugboat/wp-content/plugins/responsive-menu/responsive-menu.php(185): rm_includes_menu_theme_template() #5 /var/lib/tugboat/wp-settings.php(447): include_once('/var/lib/tugboa...') #6 /var/lib/tugboat/wp-config.php(72): require_once('/var/lib/tugboa...') #7 /var/lib/tugboat/wp-load.php(50): require_once('/var/lib in /var/lib/tugboat/wp-admin/includes/file.php on line 678