Webmin Servers Index: Error - Missing Content-Type Header

In Webmin Servers Index I added a new remote Webmin/Virtualmin server configured like this: - Non-standard port - Server type: Debian Linux (That one is a Debian 8, the current server is a Debian 6) - SSL server: Yes - Check remote SSL certificate: No - Link type: Login when icon is clicked on

When clicking on it, it asks for credentials and then I get to a blank page with large text that writes only: "Error - Missing Content-Type Header"

The fast RPC calls setting doesn't seem to matter.

Both servers are latest Webmin/Virtualmin version: 1.801/5.03 The big difference is that the current server is a Debian 6 and the remote that I add is a Debian 8.

Adding other Debian 6/7 servers works properly in the same setup. Adding the remote Debian 8 to another Debian 8 server also works. It's like they are not compatible.

Status: 
Closed (fixed)

Comments

Howdy -- we may unfortunately need Jamie's input on that one, and he's going to be without Internet access for a couple of days.

However, we can verify a couple of quick things --

If you look in var/webmin/miniserv.error when that error occurs, do you see any additional errors in there?

Also, I don't imagine there's any kind of firewall that could be blocking certain requests?

When clicking the server in Webmin Servers Index, now it doesn't ask anymore for credentials, I guess it got them stored. The error is immediately displayed.

When this happens, on host (Debian 6): Use of uninitialized value $headline in substitution (s///) at /usr/share/webmin/servers/link.cgi line 130. [08/Jul/2016:09:33:27 +0300] [IP_OF_REMOTE] /servers/link.cgi/1467717316/ : Missing Content-Type Header

On remote Debian 8: [08/Jul/2016:09:33:27 +0300] [IP_OF_HOST] Document follows : This web server is running in SSL mode. Try the URL https://HOSTNAME_OF_REMOTE:PORT_OF_REMOTE/ instead.

Yeah this does indeed sound like a bug, I believe.

Jamie, do you have any thoughts on what might be causing the above?

Are you sure that the remote system is running in SSL mode?

Yes. If I go to the http://IP:PORT/ webmin interface, it says: "This web server is running in SSL mode. Try the URL ...". This happens for both systems, all are in SSL mode. Like I've said, adding a remote Debian 8 to a Debian 6, raises this issue. Whenever combining Debian 6 with 6 and 8 with 8 thinks go fine, same settings.

Another possible problem is that the master system doesn't support the SSL protocol versions used on the remote system.

Try logging into Webmin on the remote directly, and going to Webmin -> Webmin Configuration -> SSL Encryption, and allowing all SSL protocol versions.

That was it! Had to allow TLS1.0 in this case on the remote Webmin and then it finally worked.

Thanks for your help.

Status: Active ยป Fixed