Overflow Error

[aayaanmayank]

Hi Can anyone advise why do we get overflow error and how to get rid off it.

sub mu()

Set shgroup = ThisWorkbook.Worksheets("Grouping Data_DQ")
lastrow1 = shgroup.Range("B" & Rows.Count).End(xlUp).Row



Range("I2").Select
ActiveCell.Interior.Color = vbYellow
For U = 2 To lastrow1
Set MYNAME2 = Cells(U, "I")
Set MYNAME3 = Cells((U + 1), ("I"))
If MYNAME2.Value = MYNAME3 Then
shgroup.Cells(U, "I").Interior.Color = vbGreen
shgroup.Cells(U + 1, "I").Interior.Color = vbGreen
Else
shgroup.Cells(U + 1, "I").Interior.Color = vbYellow
End If
Next U

end sub

 

[aayaanmayank]

ok thanks for your help