请问一下这段Excel vba代码出现“对象变量或with块变量未设置”是怎么回事？

Question

Private Sub CommandButton1_Click()
Dim u As Range
If [J4] = "型号" Then
u = [g4]
Else
u = [d4
End If
With Sheets("Sheet3")
r = Worksheets("Sheet3").Range("B65536").End(xlUp).Row + 1
.Cells(r, "b") = Format(Now, "yyyy-mm-dd aaaa hh:mm:ss")
.Cells(r, "c") = [b2]
.Cells(r, "d") = [a4] & ":" & [b4] & "×" & [c4] & "×" & u
.Cells(r, "e") = [h4]
.Cells(r, "f") = [i4]
.Cells(r, "g") = [J4]
.Cells(r, "h") = [k4]
.Cells(r, "i") = [l4]
.Cells(r, "j") = [r4]
End With
End Sub
谢谢！问题已解决

Answer 1

u = [d4

少了右括号
检查下是否存在表名2为"Sheet3"的表

Answer 2

ELSE的下一行少了一个]