I'm not sure if the title is right, but

I'm migrating a system made of FuelPHP to the server, but the following error has occurred and I can't get it to work properly.

Fatal error: Access to undeclared static property: Controller_Auth :: $this in ... (abbreviated)

The Controller_Auth class inherits from Basecontroller.
It seems that an error has occurred in the following description part in Basecontroller.

if (method_exists (static :: $this, 'before_controller'))
    static :: before_controller ();

I have investigated a lot, but is it NG to use "::" to call a method that doesn't declare static?

There was certainly no method that declared static in Controller_Auth.

If i don't know how to rewrite, and if you know how to rewrite, please let me know.