The tag below your question says you are using TurboTax Online. If that's true, your return is not on your computer. You could have saved a PDF from TurboTax Online.
If you have the CD/Download TurboTax software installed, are you trying to open the return by clicking on the .tax2023 file in Windows? Don't do that. Start TurboTax, then open the return from within TurboTax.
Do you have more than one .tax2023 file on your computer? Could you be opening the wrong one? You might have saved your return in a different folder, or moved it to a different folder. Search your entire hard drive for *.tax2023.
