I suspect this problem has been solved before but my understanding is that it requried adobe support, and yet adobe support (chat channel) has punted to the support community:
After a my computer received a new system board, Lightroom 6 won't run anymore. I'm hopeful that I no further description is necessary as I see posts on this topic that describe the use of a hardware signature that breaks when one gets a new system board.
How can this be resolved if the support team is unable to solve it?
Did you try uninstalling and reinstalling?
I haven't tried anything yet, as I'm still trying to learn what the real issue is, and I'm not fond of trial and error especially if there is a simple and trival motion at Adobe that can correct the problem. my install has been an upgrade upon upgrade all the way from version 4, and I don't see a reason to take the risks of such heroics if there is a simplier solution.
>>>my install has been an upgrade upon upgrade all the way from version 4
The only difference between full versions and upgrades is the serial number. Thus, when you have multiple versions installed which you have progressively upgraded over a period of time, all that's required is to re-install the latest version you own - in your case just version 6 - no need to worry about any earlier versions. Although it may seem quite drastic, I view reinstalling as routine if I hit issues such as yours.
After reinstalling an upgrade you don't need to have a "full" version already installed. Just enter your version 6 serial number (even if that's an upgrade number) then enter the serial number from an earlier version - such as version 5 - when prompted.
Hard to say what the root cause of your current issue is. However, in your position and as Peru Bob suggests, I would uninstall everything and re-install just version 6.
Possibly. Have you tried it? Did it work?
My opening post reflects what happened!
I thought you meant you'd found that link since this discussion began.
So, if it did not work, try reinstalling.
the answer is to be more persistent with Adobe support and they walk you through the process of re-activating. no re-install required
Good to hear. Thanks for the follow up.