our issue is similar to some already mentioned, but still different: I have install the Collabora Online app in Nextcloud (21.0.7) and the CODE server on the same VM (running CentOS 7.9). CODE has been installed via yum/rpm and is running on port 9980 without(!) proxy, as it is running on the same host as Nextcloud. SSL has been disabled in
coolwsd.xml. The local firewall has - for the time being - been completely stopped.
When opening an Office document, I get a white/blank page with just the Nextcloud menu. There are no errors or other messages in the system log,
/var/log/coolwsd/coolwsd.log (level set to “warning”) or in the Nextcloud log.
In the Nextcloud settings I can configure the Collabora Online server as
http://IP_OF_VM:9980 and get a green “OK” bullet. However if I try to configure it as
http://localhost:9980 I get a red connection error warning bullet.
I had the same issue also with the Docker setup and with Nexctcloud’ build-in CODE server setup.
I’m at a complete loss here and I am grateful for any pointer towards a solution or ways to debug this.