There has been alot of frustration on this issue, but it appears to have been a scheduling issue that was insurmountable with all the events going on. With the race going on Sat. and Sun. , it did not make sense , apparently to run the Challenge Series after the weekend, as the Viper Racing League and Viper Cup would have already been finished.
To Miller Motorsports credit, they have a scheduled track day set up for the 30th and they invited VOI attendees to run even though there was other items already on the agenda. You can run the entire day , with instruction ( 5 sessions ) or the afternoon with no instruction ( around $250 ). You might check if there are any openings left , as quite a few of us took up Miller on the offer.
435-277-8796 ext 1 , ask for Bill