However, I do access Virtualmin through https://vps-xxxxx.cloud:10000/, and I can use the interface without issues, but it is still logging this line. Maybe because the certificate is not considered as secure? But it is not a virtual server, it is the hostname of the vps server I access Virtualmin from. How do I fix this problem?
Having a self-signed or “insecure” SSL certificate wouldn’t be a problem… that error should only show up if the service is accessed using HTTP rather than HTTPS.
The IP addresses in the logs, are they your IP address? As it’s possible that some bots or similar are accessing your site using HTTP and generating that error.
The error message in the logfile is preceded to what it seems an ipv6 address (I obfuscated the last numbers by x).
[20/Feb/2019:06:10:48 +0100] [2405:9800:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx] Document follows : This web server is running in SSL mode. Try the URL https://vps-xxxxxxx.cloud:10000/ instead.
This is not the ipv6 address of my server.
However, when I look into “Virtual Server Summary”, the ipv6 address is the correct one (thus not the one from the logs).
When I stop using Virtualmin, the logs are stopping. I am really the one triggering these logs.