If the View Editor doesn't display all the columns in the active view, a likely cause is that the 'GrpFlag' value for one of the columns in the view is set to zero, meaning that the column is no longer marked for use in views.  Views imported from legacy system sometimes contains such fields, 'Email' being a common culprit.  The solution is to set GrpFlag = 1 for the column using a Download / Upload of the Columns table.