Access to Hyper-V or Veeam B&R Components Fails After DCOM Hardening is Enabled

After June 14, 2022, DCOM connections to Hyper-V, Veeam Backup & Replication, and other Windows-based servers may be impacted by the DCOM hardening policy activated after the deployment of the Microsoft CVE-2021-26414 security update.

Below are examples of errors that may be shown by Veeam products affected by this:
^{This list of examples errors is not exhaustive, others may exist. It is critical to focus on checking for Windows Event ID 10036.}

• Veeam Backup & Replication — operations involving Hyper-V infrastructure may fail with the error:
  

  Failed to call RPC function 'HviCreateVmRecoverySnapshot'
  

  Failed to connect to cluster <clustername>
  Failed to create Hyper-V Cluster Wmi utils: Access denied or timeout expired.
  Check if you have local administrator privileges on computer '<clustername>'.
  Possible reason:
  Specified host is not a cluster node.
  

  Failed to connect to host vmhost2
  Access denied or timeout expired.
  Check if you have local administrator privileges on computer '<hostname>'.
  Possible reasons:
  1. Invalid credentials.
  2. Specified host is not a Hyper-V server.
  

• Veeam Agent for Microsoft Windows — connection to Hyper-V infrastructure fails with error:
  

  Failed to connect to cluster 'CLUSTERNAME.contoso.com'.
  

• Veeam ONE — connection to Hyper-V and Veeam Backup & Replication infrastructures fails with the error:
  

  System.UnauthorizedAccessException:'Access denied. (Exception from HRESULT : 0x80070005 (E_ACCESSDENIED))'
  

• Veeam Recovery Orchestrator — connection to Veeam Backup & Replication fails with the error:
  

  Failed to connect to the server. Specified user is invalid or does not have enough permissions on the server.