I previously filed my 2018 taxes with TurboTax online. I need to access my state return from that year but only a .tax file is shown. How do I open the file?

[Mike9241]

you can't open the xxx.tax2018 file because it's no longer supported. I assume you did not save a PDF of the return. Check with the state tax authority to see if you can obtain a copy from them.  if not then the only way to get a copy is to use a service like Taxprinter. you would have to pay for the federal and extra for the state. Taxprinter is not affiliated with Turbotax,

https://www.taxprinter.com/ 

every year after you complete your return you should save a PDF copy because after 3 years Turbotax no longer supports the file. Also, while online sites offer the 2018 app it cannot be updated and no state return is available.