Proxmox Cannot add a new node cluster not ready - no quorum?

For some reason when I tried to add a new node I got this error

cluster not ready - no quorum?

I tried a lot of the google suggested solutions but nothing  succeeded , at last I tried this trick

pvecm e 1

and that did the trick and solved the issue .

"Failed to start Corosync Cluster Engine"  on the second node for only two nodes setup proxmox :
the problem was in /etc/hosts --> wrong IP.