Without access to your tax return, it is impossible for me to know for certain.
You should have received an email with the reason.
However, with an aging computer system that is about to be replaced and the new requirement to provide a driver's license, it has become common for New York taxpayers to need to file by mail.
Here are the mailing addresses:
If you are NOT including a payment, mail your return
to:
STATE
PROCESSING CENTER
PO BOX 61000
ALBANY NY 12261-0001
If you ARE including a payment (check or money order), mail
your return (including Form IT-201-V) to:
STATE
PROCESSING CENTER
PO BOX 15555
ALBANY NY 12212-5555