The SmackDown event scheduled for The Tsongas Center in Lowell, MA will no longer be taking place, with no make-up date announced. A notice on the Tsongas Center's website claims a "scheduling conflict" as the reason for the cancellation, while also providing refund information.
Two weeks ago, a SmackDown live event in Corbin, KY was cancelled, and blue-brand talents Kofi Kingston, Roman Reigns, Daniel Bryan, among others, appeared on that night's Raw in Cincinnati. That was the night when the brand extension's "Wild Card" rule was instituted, purportedly due to both FOX and NBC Universal being unhappy with the lower viewership totals in recent weeks, as well as the dearth of star power on both Raw and SmackDown.
While not fully confirmed at this time, it stands to reason that the sudden need to put top-tier SmackDown wrestlers on Raw, to satisfy the Wild Card rule, is likely the cause of the cancellation. The post-Money in the Bank edition of Raw takes place in Albany, NY.