Graphical Console broken?

It would seem the graphical console is broken. I set up a new Windows VM on the CM Master and when trying to use the flash based VNC I get nothing, not even the usual password and port information to manually connect. I attached a screenshot to this report. With Windows you have to use VNC to setup the IP etc so that you can then login via RDC.

Closed (fixed)


Make sure your browser supports at least one of Flash or Java - currently there is no pure-HTML/JS console.

Steffan's picture
Submitted by Steffan on Thu, 03/02/2017 - 22:53 Pro Licensee

It supports Flash - Chrome. I also tried Safari and Firefox.

Are you sure flash is enabled? Because from that screenshot, it looks like the flash object isn't even being loaded.

unborn's picture
Submitted by unborn on Sat, 03/04/2017 - 07:40 Pro Licensee

Hi Steffan and guys,

just note, google chrome be it on windows, linux or xos have always latest flash build in, so it should work right a way, but it seems to me that security policies in google chrome at Steffans machine needs to be adhered or perhaps he is using old coded vnc viewer in flash, which should be updated for security reasons, perhaps better advice would be to use html5 vnc viewer like guacamole > I hope so it helps.

Steffan's picture
Submitted by Steffan on Sat, 03/04/2017 - 09:25 Pro Licensee

It doesn't work regardless of browser. I switched to the original framed theme so I could see what was going on with the source code. The VNC viewer is not even loading in the browser. Notice the missing references.

<!doctype html public "-//W3C//DTD HTML 3.2 Final//EN">
<link rel='stylesheet' type='text/css' href='/unauthenticated/reset-fonts-grids-base.css'>
<link rel='stylesheet' type='text/css' href='/unauthenticated/virtual-server-style.css' />
<!--[if IE]>
<style type="text/css">
table.formsection, table.ui_table, table.loginform { border-collapse: collapse; }
var rowsel = new Array();
<script type='text/javascript' src='/unauthenticated/sorttable.js'></script>
<style type="text/css">
textarea,pre { font-size:120%; }
<meta http-equiv="Content-Type" content="text/html; Charset=UTF-8">
<title>Graphical Console</title>
<script type='text/javascript'>
window.defaultStatus="root logged into Webmin 1.831 on (CentOS Linux 6.8)";
<body bgcolor=#ffffff link=#376ebd vlink=#376ebd text=#000000>
<table class='header' width=100%><tr>
<td id='headln2l' width=15% valign=top align=left><a href="/server-manager/">Module Index</a><br>
<td id='headln2c' align=center width=70%><font size=+2>Graphical Console</font></td>
<td id='headln2r' width=15% valign=top align=right></td></tr></table>
<div class='ui_post_header'><tt></tt></div>
<b>Display graphical console using :</b> <b>Flash object</b>
<a href='gvnc.cgi?id=1488547976252150&java=1'>Java applet</a><br>
<a href="javascript:history.back()"><img alt="<-" align="top"src="/images/left.gif"></a>
&nbsp;<a href="javascript:history.back()">Return to previous page</a>
Steffan's picture
Submitted by Steffan on Sat, 03/04/2017 - 09:43 Pro Licensee

Usage of the java applet isn't working either. It throws a java error. ClassNotFoundException: VncViewer.class

Steffan's picture
Submitted by Steffan on Sat, 03/04/2017 - 09:47 Pro Licensee

When trying to use the java applet, it will at least print the text at the bottom.

If the VNC client does not run or cannot connect, you can use a separate VNC client to connect to port 5905 instead, and login with password xxxxxx .

Joe's picture
Submitted by Joe on Sat, 03/04/2017 - 17:15 Pro Licensee

So, flash is disabled by default, or completely gone, from several browsers. Likewise, Java is ornery.

We really need a JavaScript/HTML5 VNC client in Cloudmin, sometime soon. I'll try to tackle that soon, if Jamie doesn't have time for it.

But, anyway, I have confirmed this issue...I don't quite know why it's not working, but it definitely doesn't work in Microsoft Edge (the only browser I have that has Flash player). I've confirmed Flash is working on the Adobe test site, but I also get a blank page in Cloudmin. I'll keep poking to try to figure out what's going on.

Joe's picture
Submitted by Joe on Sat, 03/04/2017 - 17:18 Pro Licensee

I see the VNC client being downloaded in the network display. It just doesn't seem to be starting.

Joe's picture
Submitted by Joe on Sat, 03/04/2017 - 17:23 Pro Licensee

noVNC looks like the most promising VNC JS/HTML5 client, and modern VNC servers support WebSocket connections, so we possibly wouldn't need a proxy (Guacamole, another option, requires a proxy that is written in Java, to run on the server).

(I'm considering whether troubleshooting a 7 year old Flash VNC client is more work than adding support for a JavaScript/HTML5 client. And, even if JS is more work, it is probably worth it to get off of flash/java entirely.)

Joe's picture
Submitted by Joe on Sat, 03/04/2017 - 17:26 Pro Licensee

Confirmed that QEMU has WebSocket support for its VNC server (including TLS encryption)'s probably just a matter of dropping in noVNC and styling it, and configuring QEMU to setup a WSS: port for it to connect to.

unborn's picture
Submitted by unborn on Sat, 03/04/2017 - 17:59 Pro Licensee

flash is not purged from google chrome itself, its build in.. I advised him to check his browser security policies (possibly windows user) which I believe its the problem coz on my end it works (im on debian linux running google chrome browser), but I had to edit my policies in browser settings still.. instead user gave out to us I believe in frustration some html source.. ehrm. One should note that edge developed by Microsoft and flash player or whatever user have installed is not same thing as flash developed and supported by google and cannot even compete with proper code from modern browsers. Microsoft have its own issues as usual and cannot even sort its own browser to work properly. As I said earlier he should use proper tools for this so he does not need edit any policies (how to do that you can google it) ... just use some html5 code. Java applet is just very bad joke out there.. dont even bother to try it.

Steffan's picture
Submitted by Steffan on Sat, 03/04/2017 - 18:24 Pro Licensee

Unborn, I posted the HTML to show that the html object is missing from the HMTL as well as the the text string which says what port and password to use if the VNC client fails. It is not a permissions issue since I have tried every browser I have and everything flash works fine but this.

Joe, since you see it, I wonder if my CM is hosed. Jamie has the credentials to look for himself if he wants.

Steffan - was this a KVM or Xen VM?

Steffan's picture
Submitted by Steffan on Sun, 03/05/2017 - 12:28 Pro Licensee


Weird thing is I restarted Webin and no change. I rebooted the actual host server and now it works again.

Ok, I think the issue is that Cloudmin was supposed to tell you a reboot is needed, but due to a bug that message doesn't appear on the VNC page. This will be fixed in the next release.

Status: Active » Fixed
Steffan's picture
Submitted by Steffan on Sun, 03/05/2017 - 13:23 Pro Licensee

What necessitates a reboot of the host? I had 330 days up time. The reboot picked up about 6 versions newer of a kernel too. LOL.

I'm not sure, but sometimes the VNC port on the VM isn't accessing even when it is configured - and a reboot fixes it.

Status: Fixed » Closed (fixed)

Automatically closed - issue fixed for 2 weeks with no activity.