you need the ".tax2015 " datafile.
TTX supposedly does limited PDF transfers from other tax preparers (HR Block..etc)..but it is almost solely limited to personal info when it works (Name, SSN Birthdate)...and nothing else ...so it's mostly useless and easier to enter that limited data manually.
you need to search your computer for the filename ending in .tax2015....or get hold of it.
PDFs won't help you other than to enter your data manually (whenever its important).
Yes, a full PDF reading would be helpful, but they have enough trouble getting the tax software out without bugs as it is...that's just beyond their current capability.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*