Hi Audirvana. I had Audirvana 3.5 running on a 2009 Mac Pro. That Mac Pro died, unfortunately. I also have 3.5 loaded on a Mac Mini. It is currently being used for a TV. I can deactivate the Audirvana 3.5 on the Mini. But I can not on the Mac pro. I have Audirvana + running currently on a 2010 Mac Book Pro running OS X 10.11.6 (El Capitan) and I would like to install Audirvana 3.5 onto that Mac Book pro to hear the difference in sound quality between + and 3.5. Can you deactivate all my 3.5 licenses so I can relicense two different machines? Also, I have a Mac Book Air with the Apple M1 chip - will Audirvan 3.5 install and run on the M1 machine (running Big Sur). Thank you. Jeff