We upgraded from 4.6.2 to 4.9 recently. All is working well, it seems, except for the login / authentication module. When attempting to login, no username/password box appears and instead we are greeted with a module load warning:
Module Load Warning
One or more of the modules on this page did not load. This may be temporary. Please refresh the page (click F5 in most browsers). If the problem persists, please let the Site Administrator know.
Please suggest on this.