I am trying to add a remote Webmin/Virtualmin server in Webmin Servers Index but I only get "HTTP error :" without any other information.
The remote server runs on non-standard port, SSL enabled, Link type is via username and password, fast RPC calls enabled. If I try to disable fast RPC calls, I get "RPC HTTP error :", again, without any information.
How is this related to the OS version? Because the current server is a Debian Squeeze, adding another remote Debian Squeeze works but the server I am trying to add is a Debian Jessie. Also when trying to add this remote Jessie on another Jessie, works without issues, it's like the two OS versions don't work together which is really weird as it shouldn't have anything to do with it.
All servers have latest Webmin/Virtualmin: 1.801/5.03.