Be sure it's not downloading as a text file instead of a PDF.   There is a bug for some people that even when downloading the PDF, it opens as a text file and not a PDF or has gibberish when viewed with Adobe Reader.  If you click to download the PDF, but it's showing up as a text file, change the file extension of the downloaded file to PDF, and see if that solves it.   If not, then try viewing the PDF with a different browser, or downloading it first, then try opening it with Adobe Reader.

For more information on printing your return and step-by-step instructions, please see the TurboTax FAQ below and click on the version you are using.

https://ttlc.intuit.com/replies/3301671

You will need to pay before you print your 2018 tax forms or tax return. Please see this TurboTax FAQ:

https://ttlc.intuit.com/replies/3338601