ErrorException: preg_match(): Delimiter must not be alphanumeric or backslash

in /srv/library/Shared/Mvc/Application.php on line 223
#0 [internal function]: Shared\Exception\EmergencyStrategy->handleError(2, 'preg_match(): D...', '/srv/library/Sh...', 223, Array)
#1 /srv/library/Shared/Mvc/Application.php(223): preg_match('3.147.126.36', '/^((25[0-5]|(2[...')
#2 /srv/library/Shared/Mvc/Application.php(50): Shared\Mvc\Application::fixHeaders()
#3 /srv/public/index.php(8): Shared\Mvc\Application::init()
#4 {main}