Notice Was Returned To USCIS Because The Post Office Could Not Deliver It
A notice was returned to USCIS as undeliverable.
What it means
The Post Office could not deliver a notice USCIS sent you, so it came back. You are missing whatever that notice said -- which may have included a deadline.
What happens next
Update your address with USCIS right away and ask what the returned notice contained.
Official USCIS wording
On September 9, 2024, the Post Office returned a notice we sent you for your Form I-485, Application to Register Permanent Residence or Adjust Status, Receipt Number XXXXXXXXXXXXX, because they could not deliver it. This could have a serious effect on your case. Please go to www.uscis.gov/e-request to request a copy of the notice immediately. If you move, go to www.uscis.gov/addresschange to give us your new mailing address.