@tk01kj
Virginia allows amended returns 3 years from the due date of the original return including valid extensions, OR 1 year from the date that you file an amended federal return or have a federal audit finding that also changes your state tax.
Read here,
https://www.tax.virginia.gov/amending-your-return
If you had a valid extension for your 2019 return, making it due 10/15/2020, then the 3 years run until 10/15/2023.
Even if you had a valid extension on your 2018 return, making it due 10/15/2019, your ability to amend ran out on 10/15/2022, unless the reason you need to amend is that you made a change to your federal return or had a federal audit finding.
No, you can't sue. You and the state are both required to follow the law. The law says 3 years. If you didn't realize that you made a mistake, that is your responsibility to correct within the time allowed by law.
