1. Confirm the error in vcommander.log
   
   
   
   and check the target VM’s Event Viewer for Event ID 1497 with error code 1312 stating:
   "The machine MachineName attempted to join the domain DomainName but failed. The error code was 1312."
   
   
   
2. The cause may be the DomainAdmin credentials not saved in UPN format.
   • Correct format: username@domain.com
   • Incorrect format: DOMAIN\username
3. To fix this:
   • Log in to the Commander admin portal.
   • Navigate to Configuration > Credentials.
   • Select the DomainAdmin credential and click Edit.
   • Update the username to UPN format (user@domain.com).
   • Click OK to save changes.
4. Retry the failed workflow step. The VM should successfully join the domain using the WinRM module.

Outcome

Modifying the DomainAdmin credentials ensures proper authentication for domain join operations, resolving the session error and completing the workflow successfully.