Invalid command ‘PassengerResolveSymlinksInDocumentRoot’, perhaps misspelled or defined by a module not included in the server configuration April 12, 2018April 12, 2018 / Konkretor / Leave a comment You are running a redmine on your linux and upgrade passenger from 4 to 5.2 Look here https://serverfault.com/questions/895581/apache-passenger-resolve-symlinks-stopped-working-invalid-command