See: https://github.com/ONLYOFFICE/DocumentServer/issues/888

Thank you CSchmidtDD Christof T. https://github.com/CSchmidtDD

InstallConfig's Note: ds:example service is NOT disabled by default, at least not in my installation on Ubuntu using the community-edition, and, apparently it is also NOT disabled when using the enterprise-edition installation guide.

CSchmidtDD's Comments: And even if it were disabled, it messes up with the nginx config by having the link to the ds-example.conf in there. The welcome page is messed up by default that way and should not be showing an “example” index.html, at least not for an “enterprise-edition.”

If you installed the Document Server (any edition) and have the same problem - that being, the welcome page was the example index.html, then open a terminal or ssh remotely into your ubuntu or debian server and take the following steps offered by CSchmittDD to get rid of the example:

rm -rf /etc/onlyoffice/documentserver-example/  #Removes the whole unnessecary "example"
rm /etc/nginx/includes/ds-example.conf   #This will delete the link that stops nginx from starting with error like you mentioned
service nginx restart   #Should restart without problem
service supervisord restart  #As Example-Service is gone, it will re-register to only four active packets 
supervisorctl restart docservice   #Restart docservice and now you can see the green checkmark

After these steps, the OnlyOffice-Server should now show you a green checkmark on the welcome page that everything is running correctly.

Hope this fixes your problem(s). This ds example basically left the OnlyOffice Document server wide open for general public use, eating bandwidth and posing privacy and security issues.

You might suspect this had something to do with previously having removed the OnlyOffice Server “Example” that ran from the OnlyOffice Test Confirmation Page.

SEE: https://installconfig.com/doku.php?id=after_running_upgrade_ubuntu_22_04_3_onlyoffice_server_nginx_service_would_not_start