What are you trying to do? Did you download the .tax2024 from Online and trying to open it in the Desktop program? If you need to import the previous year you need the file ending in .tax2023 not .tax2024. 2024 is the current year so you need to Transfer from 2023.
And if you have the 2024 Desktop program why are you trying to move it to Online? Where did you get the .tax2024 file?
