Photoshop Elements 12 license no longer valid

I recently removed my Photoshop Elements version 12 from an old computer and installed it on a different once. But when I attempt to enter the reg code/license code, it says it's invalid.  My Adobe account still shows all the info on this edition with download link and license and invoice number, but it won't work.  Tried chat but was transferred half a dozen times to someone who handles those issues.  Never got it resolved.  Supposedly scheduled a "call back to explain to me so I could understand". Haven't received a call back and no explanatin why my software no longer is valid.  I don't believe I'll upgrade from versions 14 on my service computer if they are no longer going to be valid.