Error connecting to vnc: "No password configured for VNC auth"

So, I am using putty and UltraVNC Server/Viewer, to make a VNC connection to a lab computer in my university.

However I systematically get the error "No password configured for VNC auth".

At putty, I put the hostname of the lab computer in Port 22. Then I define the SSH tunnel :
"L5904 localhost:5904"

I run it and I log to the lab computer using my university credentials. I create a vncserver using:

vncserver :4 -depth 24 -geometry 1440x900

and that creates me a port in the server.

When I run "vncserver -list" I have:

X DISPLAY PROCESS ID
:17 2134 

Now if I try to connect to it using UltraVNC Viewer it waits for a while, then it asks for a password, which I'm not sure what it is. I put the one I defined in "vncpasswd" but it doesn't let me write the last character not sure why.

And then it gives me the error: "No password configured for VNC auth".

I'm completely stuck and I don't know what to do. Can someone please help me? I'm a noob in this and all terminal things so please be very specific in what I need to do. I will provide any additional info if needed.

Know someone who can answer? Share a link to this question via email, Twitter, or Facebook.