why am I getting "object variable or with block variable not set" error?

[dwx]

    For Each agentz In Main.Range("A6" & ":" & "A" & MainLR)

        If agentz.Offset(0, 6) <> "" Then
            
            GradDate = agentz.Offset(0, 6).Value
            GradSerial = Year(agentz.Offset(0, 6)) & Month(agentz.Offset(0, 6))
            
            x = BoardRNG.Find(GradSerial).Offset(0, 9).Value
            
             
            
            End If
            
            Next

getting the error from here

x = BoardRNG.Find(GradSerial).Offset(0, 9).Value