- Install a third party activity module of your choice.
- Visit <yoursite>/admin/plugins.php and ensure it is listed there.
- Click the 'Uninstall' link next to the module name.
- Once you see the message "All data associated with the module 'X' has been deleted from the database. To complete the deletion (and prevent the module re-installing itself), you should now delete this directory from your server" visit the mod directory and delete the module.
- Click continue.
- Notice on the next screen you will get an Invalid get_string() identifier.
- Visit <yoursite>/admin/plugins.php and notice the plugin is still listed there but has missing language strings.