I have (had) lightroom 6 on my macbook pro and my Imac. My Imac died and I purchased a new one. Lightroom tells me that I have to deactivate one of my computers before I can activate the new one. Of course the dead computer cannot be accessed. How can I activate the new Imac?
Go to "http://accounts.adobe.com" and click on the "Products and Plans" tab. You will see the activated computers listed and can de-active right from this screen. Maybe this wasn't there last year but should work now.