This error usually indicates a mismatch or validation problem with the personal information you provided in your tax filing compared to the information the Canada Revenue Agency (CRA) has on record. Changing your email address at the CRA is a good step, but the N1 error could be related to other pieces of personal information as well.
Verify Personal Information: Double-check all personal information you've entered in the tax software, such as your Social Insurance Number (SIN), date of birth, full name, and address, to ensure it matches exactly what the CRA has on record.
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