Task on VPS creation fails with the error:
Can't modify Container parameters : can't set VEth device configuration: vzctl set XXXX failed: exit code 
In vzctl.log of the node container is being provisioned to there is another error:
Unable to add IP x.x.x.x to pool: address already in use by Container XXXX
There is another container with same IP address on the hardware node.
If existing container is not registered in Operations Automation, it can either be removed or it's IP address could be changed in following way:
vzctl set CTID --ipdel x.x.x.x --save vzctl set CTID --ipadd x.x.x.x --save