Failed to run vncproxy.

[sumesh]

I installed proxmox 6.1-7 in Oracle Virtualbox and I use web browser (mozilla) to access proxmox UI in windows 10 Machine. ( that is the host of Oracle VM)
while starting virtual Machine 100, the Console states the error " failed to run vncproxy" and another error states " MAX 1 vcpus allowed per VM in a node.

 

[Stefan_R]

failed to run vncproxy

This happens if your VM doesn't start, so there's nothing to connect to.

MAX 1 vcpus allowed per VM in a node.

...and this is why your VM doesn't start. You have assigned your PVE virtual machine in the Virtual Box configuration a single CPU core. Thus, PVE believes it is running on a machine with only one core. And therefore, you can only assign at max 1 core to a given VM.

It is doubtful that you'll get this running either way, since Virtual Box does not play very nicely with nested virt AFAIK.