I loaded TT2015 onto macbook air running OS10.15.7. Every time i try to run TTT2015 it crashes with error window saying "TT2015 has quit unexpectedly" with a data dump

[Mike9241]

turbotax 2015 is no longer supported. it can not be updated even if you could get it to install.

[xmasbaby0]

You are several years too late to receive a refund for a 2015 tax return.  A refund you could have received for 2015 has been forfeited.    If you owe tax due though, the IRS wants to be paid.   You can seek paid tax help locally to prepare a 2015 return or you can use the paper forms and prepare a 2015 return by hand to mail in.

2015

Form 1040  https://www.irs.gov/pub/irs-prior/f1040--2015.pdf

Form1040 Instructions  https://www.irs.gov/pub/irs-prior/i1040gi--2015.pdf

Form1040A  https://www.irs.gov/pub/irs-prior/f1040a--2015.pdf

Form 1040A Instructions  https://www.irs.gov/pub/irs-prior/i1040a--2015.pdf

Form 1040EZ   https://www.irs.gov/pub/irs-prior/f1040ez--2015.pdf

Form 1040EZ Instructions  https://www.irs.gov/pub/irs-prior/i1040ez--2015.pdf