The installation went through, I am able to create a new textfile (Neues Textdokument) but get an error when I try to create a new document (Neues Dokument) or spreadsheet (Neue Tabelle):
No, maybe this is the problem. I was thinking it is possible without a valid cert because the creation of a simple textfile (.md) worked.
Output of /var/log/onlyoffice/documentserver/converter/out.log:
[2022-04-20T13:27:51.833] [ERROR] nodeJS - error downloadFile:url=https://srv1.test.lan/nextcloud/index.php/apps/onlyoffice/download?doc=eyJ0eXAiO ... M9M4AQ_w;attempt=3;code:DEPTH_ZERO_SELF_SIGNED_CERT;connect:null;(id=2845852478)
Error: self signed certificate
at TLSSocket.onConnectSecure (_tls_wrap.js:1514:34)
at TLSSocket.emit (events.js:400:28)
at TLSSocket._finishInit (_tls_wrap.js:936:8)
at TLSWrap.ssl.onhandshakedone (_tls_wrap.js:708:12)
Text files are opened in Nextcloud itself, there’s no Onlyoffice involved.
It should be possible but it needs to be configured, see wiki chapter about self-signed certs
I recommend to use letsencrypt as it’s simple to setup and the more secure way.