My husband passed away in July 2020 and when I tried to file my Penna. state tax return it told me I could not file a joint return for Pa. I had to create a mock return for him as single and a mock return for me as single, however when I did that it then told Pa. would not accept a return from a deceased tax payer?
I'm sorry for your loss!
Pennsylvania does not allow a joint return when the primary taxpayer is deceased and the secondary (spouse) taxpayer is alive. Since your husband died in 2020, you can file a joint federal return, but will need to prepare separate returns for Pennsylvania.
The PA returns will have to be printed and mailed in.
You can e-file your Pennsylvania return jointly if you switch the order of the taxpayers on the return so the surviving spouse is listed first. Go to Personal Info and switch the names, Social Security numbers and dates of birth so you are listed first on the tax return (your name on top of Personal Info).
If you do this, you may have to re-do other parts of the return to make sure income is being reported to the right person.
See Intuit Alumni @IreneS' answer at: Can a Pennsylvania widow file jointly for year spouse died?