Sub nSum()
Dim Rng As Range, Dn As Range, n As Long, Txt As String, Ac As Long
Set Rng = Range(Range("A1"), Range("A" & Rows.Count).End(xlUp))
ray(1 To Rng.Count, 1 To 4) 'Column count ''***ERROR LINE***************
With CreateObject("scripting.dictionary")
.CompareMode = vbTextCompare
For Each Dn In Rng
Txt = Join(Application.Transpose(Application.Transpose(Dn.Resize(, 3))), ",")
If Not .Exists(Txt) Then
    n = n + 1
    For Ac = 1 To 4: ray(n, Ac) = Dn.Offset(, Ac - 1): Next Ac
    .Add Txt, n
Else
   ray(.Item(Txt), 4) = ray(.Item(Txt), 4) + Dn.Offset(, 3)
End If
Next
n = .Count
End With
With Sheets("Sheet2").Range("A1").Resize(n, 4)
.Value = ray
.Borders.Weight = 2
.Columns.AutoFit
End With
End Sub'