I've always been able to go back and open previous versions of TT. Now I can open neither personal or business TT software without an activation code I tossed 2 years ago. I am done with Intuit.
Please call TurboTax Customer service. Here is a link: Turbo Tax Customer Service
Turbotax includes your hard drive device id as part of their activation, so if you have upgraded your harddrive, including a normal full image, it will invalidate all of your existing activations both business and personal. Their customer service has NO understanding of this issue, no procedure, they will force you through remedial and irrelevant steps only to waste hours of your time. This is the ONLY product I have had this problem with. All other products, including Quicken & Quickbooks, use just the machine device id.
Turbotax support has zero interest in actually solving your problem.