Are you sure it's for 2015? I thought only 2014 Mac had that problem. Anyway....here's an answer. It's for 2014 but applies to 2015 too. Replace .tax2014 with .tax2015.
See macuser post here
https://ttlc.intuit.com/community/after-you-file/discussion/i-am-unable-to-print-a-prior-year-return...
Or try to find a Windows computer. The .tax files can be opened by both the Windows and Mac programs. But you would have to install the 2014 program which might be impossible. Even if you have the CD you wouldn't be able to update the program or download any states you need. Unless you know someone with 2014 still installed on Windows.
Or try www.taxprinter.com . They say they can convert 2014 to pdf. They are not related to Turbo Tax and it does cost. You send them the .tax2014 file.
