Reply To: Problem with MB Settings Page in custom plugin with class-tgm-plugin-activation

Hello,

When do you call this statement add_filter( 'mb_settings_pages', 'prefix_options_page' );? Do you call it directly from the main plugin's file?

The filter mb_settings_pages must be called before admin_menu action, which is used to add admin menu. That action fires quite early, before admin_init, so if you call it inside a hook, it might not work as expected.