This is severe and if unamended inspection of your tax returns by USCIS will lead them to believe yours is a sham marriage, entered into just to procure a green card to the foreign national. Run to have your tax returns amended by any accountant or CPA.
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You should strongly consider having an attorney accompany you to the interview and assist you with compiling evidence. At the least, you should bring proof that the tax filing was being amended before you got this interview notice letter, but I am not sure that will be enough at this point.