@nasim
As i can see it, the error is on the content of you cluster.conf file, this file should be the same in all PVE Nides !!!.
I think that you do not respect the syntax of this configuration file and the rules of the cluster configuration..
My suggestion are:
A) Rules generals tha you need to know:
1- Don't use your Quorum Disk unless necessary to complete a group of odd nodes (or add a Node PVE more to Cluster)
2- The /etc/pve/cluster.conf file should be the same in all Nodes of a same PVE cluster.
3- "Always" that you want modify the /etc/pve/cluster.conf file, you should know that do:
3.1- Run: cp /etc/pve/cluster.conf /etc/pve/cluster.conf.new
3.2- Modify the /etc/pve/cluster.conf.new file according to your needs
3.3- Into this file, for the config_version value you must add an integer and put this number replacing the previous
3.4- On the PVE GUI of the same Node click in the option "Activate" of the tag "HA"
Note: if you don't have errors, the new config will be activated in all PVE Nodes of the same Cluster, otherwise not take effect. This option is only for check the syntax, but you should know what you are doing
B) For your case:
1- You must correct the settings of your cluster.conf file, and think that should do it in the PVE Node that have Qurum (light green on PVE GUI), then the other Nodes can take the configuration of this Node with the configuration modified (for do it more simple, may be necessary restart the other Nodes)
I don't have practice with unicast, but for help you, I show a cluster.conf file that should work in multicast mode, (then for the unicast, you must adapt it to your needs, and the <rm/> key may be unnecessary):
<?xml version="1.0"?>
<cluster name="master3" config_version="14">
<cman keyfile="/var/lib/pve-cluster/corosync.authkey">
</cman>
<clusternodes>
<clusternode name="node1" votes="1" nodeid="3"/>
<clusternode name="node2" votes="1" nodeid="2"/>
<clusternode name="node3" votes="1" nodeid="1"/>
</clusternode>
</clusternodes>
<rm/>
Awaiting that this help you, i say goodbye