There are numerous thread on other forums about this. Long story short. Both USPS and USCIS tracking said my physical green card was delivered, but I receive nothing. Other forum users are saying USPS tracking system is flawed.... I called usps and uscis. USPS said they are looking into it and will call me back, but i doubt im ganna get a call back. USCIS said they are not responsible anymore because the mail has been picked up by usps. Their only suggestion is to file the i-90 form, which is going to cost me another $450 as far as I know.... Anybody have this experience? Any suggestions on what to do next?