I have a proxmox-Cluster consisting of two nodes. I had the exact same problem as described here, but no solution worked.
After many hours of not finding out why, I finally hit the solution and just wanted to share: I had some scripts running in .bashrc of root, like displaying of lxc ("lxc-ls"), qm ("qm list") and RAID status. It's noce to see this when logging in. But vncproxy does not seem to like this. After I deleted the lines, vncproxy started working in my cluster. Puh!
Maybe this can save anyone some hours...
After many hours of not finding out why, I finally hit the solution and just wanted to share: I had some scripts running in .bashrc of root, like displaying of lxc ("lxc-ls"), qm ("qm list") and RAID status. It's noce to see this when logging in. But vncproxy does not seem to like this. After I deleted the lines, vncproxy started working in my cluster. Puh!
Maybe this can save anyone some hours...