The 2017 tax data file, which has a file extension of .tax2017 can only be opened by the TurboTax software for tax year 2017.
TurboTax does not support tax year 2017.
If you do not have the 2017 TurboTax software, you can use this website to get a PDF from the tax data file, but it will cost you and TurboTax does not support this website - https://www.taxprinter.com/