Error - Cannot convert system.date.time? to system.date.time

Question

Hi

  In below code i am getting error - Cannot convert system.date.time? to system.date.time

List<View_SessionDeliveryParticipant_Detailed_Report> objResult = bALSessionDeliveryParticipant.GetSessionDeliveryParticipantList(Result.StartDate,Result.EndDate, mentor, group);

Thanks