Encore CS6 serial number issue

I have Encore CS6 installed on an older computer that I got when I purchased the Production Premium CS6 back in 2012.  I have been using Creative Cloud for years now, and up until a year or so ago, the old version of Encore worked since I also had Premiere CS6 still installed on that computer.  Now, for the last year or so, Encore is asking for a serial number.  I don't have the serial number with the old disks, and I can't look it up in the "find your serial number" page because I no longer have the email account I used from back then (I got it through a public school and have since changed districts and my account is gone).

Is there any way I can get past this serial number issue?

Thank you!