CS6 serial number not accepted

I hope someone here can help me.  I had two Mac computers but one is nearing "death", so I just purchased a new Mac computer. I want to install Adobe Photoshop CS 6 on this new computer. I uninstalled CS6 on the old computer and should now have the ability to download the software to this computer.  Because my new computer has Sierra 10.12.6 which I understand from reading this forum that it can pose problems with CS6, and after countless hours and frustration, I found a work-around ( Installer > Show package contents > Contents > Mac OS > Install) and followed that.  But when it asked for my old serial number, it said the serial number "is valid but a qualifying product could not be found on this computer." It lists CS3, CS4 and CS5 as well as the extended versions of CS 3, 4, 5, and 6 on the drop down menu but I don't have the extended version of CS6 and CS6 is not listed.  I'm at my wits end and don't know what the problem is now. I hope someone can help me.  Thanks in advance.