OnlyOffice Integration in Nextcloud (ONLYOFFICE cannot be reached. Please contact admin)


I have a question regarding OnlyOffice Integration into my nextcloud. Both installations (Nextcloud and OnlyOffice) work completely fine on their own (except slow WebDAV speed on Nextcloud), but trying to open a Document results in an “ONLYOFFICE cannot be reached. Please contact admin” Error!

OpnSense Firewall with HAproxy
listening for

  • cloud. mydomain .com
  • office. mydomain .com
    forwarding (with SSL offloading) to
  • vs-cloud01. mydomain .com
  • vs-onlyoffice. mydomain .com

Installed via Snap on Ubuntu 20.4.3

  1. The following settings have been made:
    Set Accepted Hosts
    sudo vim /var/snap/nextcloud/current/nextcloud/config/config.php
    a. Add
    ‘trusted_domains’ =>
    array (
    0 => ‘ipaddress’,
    1 => ‘cloud. mydomain .com’,
    2 => 'vs-cloud01. mydomain .com,
    3 => ‘vs-cloud01’,
    4 => 'cloud01. mydomain .com,
    b. For OnlyOffice Integration, add
    ‘allow_local_remote_servers’ => true,
    ‘onlyoffice’ =>
    array (
    ‘jwt_header’ => ‘AuthorizationJwt’,),

Installed via Installation-Script not using Docker on Ubuntu 20.4.3

  1. The following settings have been made:
    Settings – Customization
    1.1. DNS Settings
    Custom domain name Check
    domain name office .mydomain. com

The screenshots show my current integration settings (integration itself works flawless), the possibility to open OnlyOffice and Nextcloud via the given link:

Anyone has an idea, what I’m missing?

Many thanks and best regards

There are 47 results on the search for “ONLYOFFICE cannot be reached. Please contact admin”…
got about 20 of them, nothing helped in my case… and my nextcloud log is empty :frowning:
(one thing I’m currently trying: 73050/7 but as the apps page of next cloud is down, I’m currently unable to reinstall the OnlyOffice App)

Had to add spaces to my configuration “links” due to the limit of posting max. 4 links for new users