For my 2015 tax bill, I used Turbotax to pay my state taxes to MA, my permanent residence. But in summer 2015 I had earned a one time fee for consulting with a firm in CA, for $2,500. Earning anything outside my regular paycheck is unusual and I forgot about it and did not include the $2,500 as earnings. Now in 2020 the state of CA has charged me with not paying state income tax. I spoke with a CA state tax office advisor who said I should file an amended 2015 return, acknowledging the $2,500 income that was earned from a CA firm, and show that I filed and paid MA state tax.
My question: can I use Turbotax to file the amended return? Are there any examples of how to do this? I do have my version of 2015 Turbotax but it crashes after "No tax form updates at this time" when I hit OK.