Looking for logging into the Owncloud File Not Found site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Owncloud File Not Found site. After that you can login as usual with your login credentials.
https://central.owncloud.org/t/404-page-not-found-after-successful-owncloud-setup/11581
https://central.owncloud.org/t/solved-upgrade-to-10-0-9-results-in-owncloud-not-found-error-404/15628
https://forum.owncloud.org/viewtopic.php?t=5064
https://central.owncloud.org/t/404-not-found-after-successful-setup/12987
https://github.com/owncloud/core/issues/23217
https://github.com/owncloud/core/issues/22970
https://github.com/owncloud/core/issues/24272
https://askubuntu.com/questions/747811/404-not-found-cant-access-login-page-after-upgrade-to-owncloud-9
https://serverfault.com/questions/528448/message-file-not-found-when-trying-to-install-nginx-owncloud
https://doc.owncloud.com/server/10.0/admin_manual/issues/general_troubleshooting.html
https://stackoverflow.com/questions/23923381/owncloud-not-available-after-installation-on-ubuntu-server-14-04
https://help.nextcloud.com/t/the-requested-url-nextcloud-index-php-apps-files-was-not-found-on-this-server/10472
https://superuser.com/questions/1051195/apache2-debian-owncloud-9-not-found-after-oc-update-8-2-to-9