For some reason I get this message in my log,
Class "Foo::Controller::OAuth" is not a controller
However, in my Foo::Controller::OAuth I have at the very top,
use Mojo::Base 'Mojolicious::Controller';
What other things can cause this error?
You can get this error if the package name is wrong. For example
package Foo::Controller::Oauth; # notice the lower-case a in 'auth'
use Mojo::Base 'Mojolicious::Controller';
vs
package Foo::Controller::Oauth; # notice the upper-case A in 'Auth'
use Mojo::Base 'Mojolicious::Controller';