Headers already sent - cannot access my website!

When I enabled canoncirl URLs in the admin, all of a sudden I cannot access the site!!

I get the following error:
Whoops \ Exception \ ErrorException (E_WARNING)
ini_set(): Headers already sent. You cannot change the session module's ini settings at this time

I have set back the 'canonical_url' setting via the application / config / site.php but the error keeps showing...

Any hints?

jwulff replied on at Permalink Reply
It keeps trying to go to the HTTPS :(
jwulff replied on at Permalink Best Answer Reply
Got it working again
enabled must be false!

'seo' => [
'canonical_url' => 'http://www.URL.dk',
'canonical_url_alternative' => '',
'canonical_tag' => [
'enabled' => FALSE,