In a cluster environment, WMI is often used to share information and notification within the nodes. Some of the cluster issues/error due to the WMI is as listed below:

“RPC Server Unavailable” error.
Access is Denied.
The computer ‘Node1’ could not be reached.
Failed to retrieve the maximum number of nodes for ‘{0}’.
The computer does not have the Failover Clustering feature installed. Use Server Manager to install the feature on this computer.
Note: first confirm you have installed the Failover Clustering feature on this node

In above case we need to make sure that the WMI is working fine and this can be confirmed following the steps listed below:
Make sure that the WMI service is up and firewall settings.

1. Launch CMD
2. Type “WBEMTest” (without quotes”).
3. The Windows Management Instrumentation Tester will launch
4. Select Connect
5. Namespace: Root\MSCluster
6. Select Connect and if you see more options available, it means you are connected and WMI is working
7. Click on Query and enter SELECT * from MSCluster_Resource to confirm (any error shown represents WMI issue).

Thanks,
WinteAdmin