Try contacting Adobe directly. This is a user to user forum but only Adobe staff can deal with activation issues. They may need to re-set the activations from within your account. Click the link below and scroll down to Individual “Sign-in to contact us” and you should be able to start an on-line chat session. As you have an older product make clear you are looking for activation, not support.
I have an Windows machine and upgraded my PC on a new SSD.During the installation i should fill my account.
Now, after the test period i must activated Lightroom 6.14 and there is the Problem.
I will start Lightroom and the next window says LogIn required, after click on the "Sign In" button, the next window is check the serialnumber and i should check my connection to the internet, but conection is perfect, after press on "check" the process it will be repeated.
I have called the support, on this side(Adobe) everything is okay i should check by my side Firewall or others.
So i have deactivated my Firewall but i could not fixed the problem...