Hi Gurus:
The on-line package tracking indicate my Fedex express sent to VSC (St Albans)were re-routed to Williston to be delivered.
If on 5-11 5pm, it already reached VSC, VSC can reject your filing (and let you know your case is returned in 2 or 3 weeks).
Fedex reroute is not a problem, Fedex is one of the courier services cooperated with USCIS service centers.