could not buy spy option at interactive brokers question

Hi, I have never had this happen before, but at interactive brokers, I was trying to buy a spy 248.5 call for sept 29th, and it would not let me buy it. It said something like invalid contract or something, don't remember exactly what it said. Then I tried buying the 27th call instead, and had no problems. Do you have any idea what happened? Thanks.

 

I think, only closing transactions are allowed on fractional ($xxx.50) options for this expiration

 

Yeah I saw this today:

SPY 9/29 Options

The OCC is no longer accepting opening transactions for $0.50 increment strikes on SPY options expiring 9/29/2017. Submitted orders will be canceled by the exchange.