Why is there a blank screen when opening documents through Onlyoffice?

Question

ownCloud/Nextcloud

There are two servers, geographically separated, on different IPs.
1) Server A with Nextcloud 13 installed, domain example.com, https from Letsencrypt.
2) Server B with Onlyoffice Document Server installed, subdomain office.example.com, https from Letsencrypt.
Onlyoffice application has been added to Nextcloud, https://office.example.com is specified as the address of the document server,the connection is established, the request from Server A wget office.example.com fulfills, index.html is downloaded, no errors. But when opening any document in Nextcloud, the only reaction is a blank white screen, and nothing else. I have not configured ipfilter yet, the secret key is not used, the OO installation is clean on a fresh system. In a previous installation, Server B had both ipfilter and a private key configured, and the response was the same.

Answer 1

Well, in general, if this question is still relevant, then I had this problem due to the fact that in the "Server address for internal requests of the document editing service" which is located in settings -> advanced. It is necessary to put down https, not http in all places for Onlyoffice. In general, it is better to run onlyoffice on the same server as owncloud.