Reset Password page says "is not an apple id"
We recently replaced a hard drive. After restoring stuff, I tried to play a song on iTunes and got the message saying "This computer is not authorized..." and it gave me a chance to enter the password with the Apple ID already filled in. No password worked, so I just clicked "Forgot?" and was taken to the Apple page to reset the password. The Apple ID was already entered, so I clicked "continue". At that point, however, the page popped up a message saying "<myemail@address> is not an Apple ID".
I don't understand because that is the email address with which the song was purchased. What do I do now?
iTunes 12.3.2.35
Windows 7
iTunes-OTHER, Windows 7
