Kyle,
Get rid of the “public” in front of function. I ran this and everything works great.
function exclude_role($roles) {
//Hide Defualt Roles
if (isset($roles['author'])) {
unset($roles['author']);
}
if (isset($roles['editor'])) {
unset($roles['editor']);
}
if (isset($roles['subscriber'])) {
unset($roles['subscriber']);
}
if (isset($roles['contributor'])) {
unset($roles['contributor']);
}
return $roles;
}
add_filter('editable_roles', 'exclude_role' );