I've had an Ubuntu VM running on my server for several months now. I connect to it using the noVNC option built into Unraid. Yesterday I tired adding a second Ubuntu VM for a new task. After starting the new VM I was unable to connect to either it or the old VM. NoVNC simply reports "Failed to connect to server". I deleted the new VM but still could not connect to the old VM. I tried restoring from a saved libvirt image, which involved resetting the server altogether, but still could not connect. My only other VM is a Windows machine hooked up to a GPU and monitor, this works fine.

 

I get the following error in the Unraid logs each time I attempt to connect to the VM via noVNC:

 

Tower nginx: 2021/03/15 09:30:55 [error] 10278#10278: *1827 recv() failed (104: Connection reset by peer) while reading upstream, client: 10.10.20.164, server: , request: "GET //wsproxy/5700/ HTTP/1.1", upstream: "http://127.0.0.1:5700/", host: "10.10.20.2"

 

Any advice on how to fix this would be much appreciated.

 

I am running Unraid 6.9

 

Thank you

It turns out the problem was not with the server but rather with Chrome. I was able to get noVNC to connect using Edge, which prompted me to restart Chrome and then it worked. I had tried using Edge to connect previously with no luck, but I don't think I had tried again since restoring the libvirt image. Glad it is working now, but I still do not know why adding the new VM broke things in the first place. 

I saw this too, just now on 6.11.1. Thanks to your suggestion I opened unraid in an incognito window and that worked fine.