Hi, We got an issue comparable to the one already described (see 245938), using the same demo project 1) I add LastDeliveryDateTimeLocal column 2) remove groups 3) click on "Start async notifications" 4) click on the filter icon next to "LastDeliveryDateTimeLocal" column name 5) uncheck some values (08/09/2016, 11/11/2016, 03/01/2017) 6) click Ok => NullReferenceException