When running the SQL Processing Wizard to process the SQL Server, getting the following error:
Cannot create login 'TARGET\TestUser'. Error: Windows NT user or group 'TARGET\TestUser' not found. Check the name again.
WORKAROUND:
Run the resource processing for the SQL Server and move / join the SQL Server to the Target domain environment.
Once the SQL Server is in the Target domain environment, re-run the SQL Processing Wizard to update the user login.