How can I activate an old version of Adobe Encore (1.5)?

I am trying to re-install my purchased version of Adobe Encore 1.5.  I realize this program is several years old and no longer supported, however, it still suits my needs and I would like to continue using my purchase.  Since the activation site is no longer available, I am unable to authorize it after install.  Is there a fix for this?  I've contacted Adobe support via chat and was told that chat/phone support will not address this issue since they no longer support the program.

Thanks in advance for any help!