Can't install Elements 12?!

[Dawnpoint]

I got out my old Elements 12 discs to install on my Mac Pro running Mojave. The validation step says "Connect to the internet" and obviously I am.

How do I fix this?

Secondly, I attempted to register my serial on my profile and it said my serial is already in use!!

How do I get this old copy working again? I can't afford the newest stuff (which is why I'm still using a Mac Pro on Mojave)!

[Peru Bob]

I attempted to register my serial on my profile and it said my serial is already in use!!

By @Dawnpoint

Please go to Adobe Customer Service and only ask to have your activations reset (make sure to sign in to your Adobe account first and allow popups on your browser):
https://helpx.adobe.com/contact.html?rghtup=autoOpen will automatically open the chat window.
Type "Agent" in the chat box to bypass the chatbot and be connected to a person.

You may also be able to contact Adobe by phone:
https://helpx.adobe.com/contact/phone.html

[Dawnpoint]

They require an active plan to get live support?? What crap. I just want to use my old software.