I am using Utrawebgrid to display a small set of records. No updating is to be done. The grid is for read only usage. I have a column that I wish to group by which seems to work appropriately. After the grouping operation I have three or four child bands each containing a couple rows of grouped information. I filter a column in a child band and that seems to work. However, if I attemt to remove the original grouping column at this point, the grid throws an error, basically saying object not set followed by a stack trace.

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below

[NullReferenceException: Object reference not set to an instance of an object.] Infragistics.WebUI.UltraWebGrid.StateChangeProcessor.ProcessFilterColumn(StateChange stateChange, UltraGridColumn column) +2502 Infragistics.WebUI.UltraWebGrid.StateChangeProcessor.ProcessChanges() +5955 Infragistics.WebUI.UltraWebGrid.UltraWebGrid.ProcessChanges(StateChanges stateChanges, Boolean fireEvents) +439 Infragistics.WebUI.UltraWebGrid.UltraWebGrid.LoadPostData(String postDataKey, NameValueCollection values) +5479 System.Web.UI.Page.ProcessPostData(NameValueCollection postData, Boolean fBeforeLoad) +346 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1743