Since you have a PDF of the 2019 file, I wouldn't bother recreating the .tax2019 file. Just install TTX 2020 and recreate the .tax2020 file. Especially if you need it to import into your 2021 tax return since you've only got 12 days left to e-file it before the IRS shuts down e-filing for the 2021 tax filing season. You'll be able to enter the history manually. For example, if you have a rental property, the program will estimate the prior year's depreciation based on the dates you enter, and you can change that estimated amount if necessary. Usually in this scenario, it's not necessary if you enter the dates "exactly" as they are on the worksheets in the PDF files.
For others reading this thread, now you see why I harp not just on backups, but on hard copy PDF printouts of "EVERYTHING" to include all calculation forms and worksheets. While it's time consuming entering everything again, it's not lost permanently and forever.
