Resolve problem: https://codex.ww.wp.xz.cn/FAQ_Troubleshooting#How_to_deactivate_all_plugins_when_not_able_to_access_the_administrative_menus.3F
Via FTP or your host’s file manager, navigate to the wp-contents folder (directory)
Via FTP or your host’s file manager, rename the folder “plugins” to “plugins.hold”
Login to your WordPress administration plugins page (/wp-admin/plugins.php) – this will disable any plugin that is “missing”.
Via FTP or your host’s file manager, rename “plugins.hold” back to “plugins”
I rename the plugin name, exm. WPUser Frontend to WPUser Frontend1. This helps.
