Exception: getSiteModelLink failed: unknown url /doc/

Details:

#0 /var/www/vhosts/emporia.de/httpdocs/_frontend/Links.class.php(21): Controller->getSiteModelLink('/doc/')
#1 /var/www/vhosts/emporia.de/httpdocs/init_links.php(8): Links->addLinkFor('Manual', '/doc/', '{{Titel}}', 'Details', Array)
#2 /var/www/vhosts/emporia.de/httpdocs/init_virtualizer.php(30): include('/var/www/vhosts...')
#3 /var/www/vhosts/emporia.de/httpdocs/virtualizer.php(71): include('/var/www/vhosts...')
#4 /var/www/vhosts/emporia.de/httpdocs/virtualizer.php(136): Virtualizer->loadSite()
#5 {main}