Nothing happens

@jfsberg first things first, it auto-saves the settings.

Can you please open your wp-config.php file and check if you have some salt keys? They’ll look something like this:

define('AUTH_KEY',         '+2LoS2JVBGhJ0Jrg9qlgpkLV9MiAJ+j1lQBRmk1imycpujc8TFcJ9tfT1BLPoIfckrEiOxX0bjj9H+igr8u8Ug==');
define('SECURE_AUTH_KEY',  'zohCO5I4URWGWuZW25L5kP5WgilG9b0qD5w5dQHO5jKoBSHIa+1q/y9SBU/Cu0JIbNuv70G+p9PLvhK2mPyCCQ==');
define('LOGGED_IN_KEY',    'QJ5XquQvrS+F8YueWyhVuIWSCmerh6ONJmC2DxZ6QUGDNyGtqPdhGoRSNQg9ekMf3XPIvfhyWCtYfXCeWWi7yw==');
define('NONCE_KEY',        'zgaEcD3svYHyB21C5u8t4VGBlsqrLsdV7K5g+YbpOeAo+rMYKjfNu2I2G+hCnE2FSQvPAZSKRa2OmQvakHr6ow==');
define('AUTH_SALT',        '76lTyi795JQnyuw3AnE+srzzUOnhN1GdIqjinFbwbvfKmEpGJyUuEF2FSsqrRSCsGdYgMansNOaw9g5elczUgg==');
define('SECURE_AUTH_SALT', 'Z+yV/cvkr3L763TUjTA+oa1wMiZi9RbrCAc5GsNgOPhe3w1k8fU7ftu0cvRWrfScgJIbPfOlYfxQdY+/pIMEAg==');
define('LOGGED_IN_SALT',   'IfcNWpTL3OcZrMo4I1IbZoxT5MVgmvCsYpI1kOrp/sziJdFt8056J1jIfc3nxhwAEkUGdkUaFChla9LKOVILEA==');
define('NONCE_SALT',       'MjQ+jUiux8vpc8/gj/DgZ8pS6Zmi16jlzpp+Xv6+76SUbrM3cn6F0dKQ8/91XlUEVRpVTqGO5OMBs1plOe+9qQ==');

** To open the file, you can access it via FTP.

Well, can you please replace them with a new set of keys from this link https://api.wordpress.org/secret-key/1.1/salt/

Hi Jan,

Maybe the salt keys on that site are not set correctly.

What I asked you to do is:

1- Backup your wp-config.php file.
2- Delete all keys in the wp-config.php (the keys I mentioned in my first reply).
3- Go to https://api.wordpress.org/secret-key/1.1/salt/, it’ll generate a unique set of keys for you.
4- Add them to the config file.

Now, you’ll need to login again to the site. Once logged in, try the plugin again.