Do you get an error message when you try to download it?
If you are familiar with your printer settings, try temporarily disabling the printer spooling feature (which attempts to save the whole file before starting to print).
Try going through the FILE section again, and choose 'View/Print/Save' to try to save it to your desktop, then open it with Adobe or your PDF reader from there.
If you're using TurboTax Online, it's always good to close the program, clear your Cache and Cookies, and try again.
Here's more workarounds from other users on Can't Download Tax Return to Print.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"