I got the notices yesterday and I checked the case online. It doesn't recognize the number I entered. It start with MSC, not WAC or SRC. Is this something new? On the status online webpage it says below. I checked the FAQ but nothing related to this issue.
To view the status of a case, please enter the corresponding application receipt number. The 13-character application receipt number can be found on application notices you have received from the USCIS. It begins with three letters such as (EAC, WAC, LIN, or SRC). Dashes ("-") should be omitted when entering a receipt number. However, all other characters, including asterisks ("*"), can be included if listed on your notice as part of the receipt number. See the FAQs for additional information on this system.