In additional to these.
https://help.nextcloud.com/t/onlyoffice-error-while-downloading-the-document-file-to-be-converted/45195/17?u=acecombat2
Don’t forget to overwrite the cli < tested it works. on Nextcloud version 16.x.x
The following is an example:
'trusted_domains' =>
array (
0 => '192.168.0.8:80', #for local access
1 => 'myddns.domain.org', #access externally
2 => 'myddns.second.domain.org', #access externally second domain if you have one.
),
If nextcloud are behind reverse proxy webserver,
'overwrite.cli.url' => 'https://myddns.domain.org:port', #it forcefully nc to use this as base link
'overwritehost' => 'myddns.domain.org:port', #it forcefully nc to use this as base link
'overwriteprotocol' => 'https', # force to use SSL because of reverse proxy by let's encrypt
Using Docker Images Nextcloud, OnlyOffice and Caddy Webserver.