Please explain in detail what you are doing. I suspect you are trying to transfer the 2024 data into a new 2025 return. How are you attempting that? What screen has the "continue" button you refer to?
You do NOT try to open the *.tax2024 data file. We can tell you more about the transfer process once we understand your situation.
Start by making it clear if your 2025 product is desktop software or Online TurboTax. If you are using desktop software, is it for Windows or Mac?
How was the 2024 return prepared? i.e., was the *.tax2024 data file prepared online in your account, or was it prepared in 2024 desktop software and resides on your computer?