Flow designer gives the following error when a PowerShell step is used:
Error: Authentication Failure with the local MID Server Service Credentials.
When Discovery is scheduled for the Windows devices, It checks all the credentials for Windows in our instance for the device we are trying to discover. After Powershell tries all the credentials in the instance and it fails to login with any of them. Next by default, It attempts to login by using MID Server service credentials.
Add this Parameter to the "Configuration Parameters" related list of the MID Server record: mid.powershell.local_mid_service_credential_fallback = false
Note: After changing the parameter, you need to restart the MID Server, which can also be done from the "Restart MID" related link on the MID Server record.