This was actually the answer (received via email). The original command I was using was:
<pathToBesAdmin>\BESAdmin.exe /service createtokenkey /sitePvkLocation=<path+license.pvk> /sitePvkPassword=<pvkPassword>
When I dropped the “service” out of the command:
<pathToBesAdmin>\BESAdmin.exe /createtokenkey /sitePvkLocation=<path+license.pvk> /sitePvkPassword=<pvkPassword>
… I got the “Token key successfully created” popup!!!