If you are trying to open the tax data file, which has a file extension of .taxyyyy, where yyyy is the tax year of the file, eg .tax2018, that file can only be opened by the TurboTax software for that year.
The Adobe Reader can only open files with an extension of .pdf, not the tax data file.
To access your current or prior year online tax returns sign onto the TurboTax website with the userID you used to create the account - https://myturbotax.intuit.com/
Scroll down to the bottom of the screen and on the section Your tax returns & documents click on Show. Click on the Year and Click on Download/print return (PDF)
