· I need to swap a subscription (I have two) from a PC that i no longer have access to a mac book pro. Do not want to move the subscription used by my Nucleus. I have followed the instructions but the "switch" dialog does not engage.
No need to worry about the Switch dialog! You can simply install Roon on your MacBook Pro and log in with your Roon account. During the login process, Roon will detect that your account already has an active server elsewhere and will prompt you to deauthorize the old PC — this is completely safe to do since you no longer have access to it anyway.