CollabVM Server 1.x/Problems

This page will attempt to document the common problems people face when trying to start CollabVM Server.

On Ubuntu 16.04/18.04/Debian 7/etc, when I attempt to start the server, I get a message that libvncclient.0 could not be found.
If you are receiving this error on Ubuntu 14, please make sure that libvncclient1 is installed (sudo apt install libvncclient1). On Ubuntu 16.04 and 18.04, type sudo apt install x11vnc.

This is because CollabVM Server is compiled with an older version of libvncserver. Ubuntu 16.04, 16.10 and Debian 7, 8 by default come with a newer version of libvncclient in their repositories, which instead of being named libvncclient.0, is named libvncclient.1. Fear not, however. CollabVM Server is fully compatible with the newer libvncserver, but a symbolic link needs to be created.


 * amd64:
 * i386:
 * armhf:

Start the server again, and it should work just fine. This does not need to be done on Ubuntu 14.04.

When I attempt to start the server, I get a message that libuuid.so.16 could not be found.
Type the following command and try again:

On amd64:

On i386:

It should now start and you should be good to go. This is not necessary on CollabVM Server 1.2.8.

When I attempt to start the server, I get a message that libpng12.so.0 could not be found.
This is a common error on Ubuntu 16.04, Ubuntu 18.04, and Debian 8. This is due to libpng16 replacing libpng12. You can either upgrade to CollabVM Server 1.2.8 which uses libpng16 or use the following commands on Ubuntu 16.04/18.04 and Debian 8:

and try again, if it doesn't work or you're on a newer version of Ubuntu which does not have this package, try using the following commands:

Replace "amd64" with your architecture if necessary.

When both packages are downloaded type

Now libpng12 should be installed and ready to use for CollabVM Server.

On Windows, when trying to create a VM, I get an error that says "Root value is not an object".
This is due to an issue with RapidJSON, if you want to specify a path on Windows, just use double backslashes, like this:

When trying to start the server, I get the message "error listening on port (x): Underlying Transport Error" or something similar.
If you shut down the collab-vm-server without stopping the VM first, or the collab-vm-server crashed while running the VM, this error will occur. Wait a few minutes and try again.

If the error still persists after several minutes make sure that  or similar is not running (use Task Manager on Windows or pidof qemu in nix to check). If it still doesn't work make sure the port is not in use by another program. On Linux and other nix-like operating systems some ports like 80 and 443 require root access.

If you are receiving this error on Windows XP, it is likely because you do not have IPv6 installed. You need to install IPv6 support for this OS by going to Start -> Control Panel -> Network Connections -> Right click on your connection -> Properties -> Install -> Protocol -> Microsoft TCP/IP version 6. Modern editions of Windows should come with IPv6 support already installed but you could try repeating this step on newer versions if needed.