运行时错误 50290 方法与对象“_global”相交失败

问：

我是 VBA 编程的新手，并且正在努力遵循以下代码，该代码的目的是具有一个具有多个选择的下拉列表，该列表仅限于某些单元格。 问题是，当只打开带有VBA的文件时，VBA工作正常。 当我并行打开另一个 excel 文件并尝试使用下拉列表时，我收到错误说明：运行时错误 50290 方法与对象“_global”相交失败（错误出现在 If Not Intersect（Target， ActiveSheet.Range（“Mehrfachauswahl”）） Is Nothing Then 中） 我已经搜索了类似的情况，但没有找到合适的解决方案。 代码如下：

Private Sub Worksheet_Change(ByVal Target As Range)

    Dim OldVal As String
    Dim NewVal As String
    
    ' If more than 1 cell is being changed
    If Target.Count > 1 Then Exit Sub
    If Target.Value = "" Then Exit Sub
    
    If Not Intersect(Target, ActiveSheet.Range("Mehrfachauswahl")) Is Nothing Then
    
        ' Turn off events so our changes don't trigger this event again
        Application.EnableEvents = False
        
        NewVal = Target.Value
        
        ' If there's nothing to undo this will cause an error
        On Error Resume Next
        Application.Undo
        On Error GoTo 0
        
        OldVal = Target.Value
        
        ' If selection is already in the cell we want to remove it
        If InStr(OldVal, NewVal) Then
        
            'If there's a comma in the cell, there's more than one word in the cell
            If InStr(OldVal, ",") Then
                If InStr(OldVal, ", " & NewVal) Then
                    Target.Value = Replace(OldVal, ", " & NewVal, "")
                Else
                    Target.Value = Replace(OldVal, NewVal & ", ", "")
                End If
            Else
                ' If we get to here the selection was the only thing in the cell
                Target.Value = ""
            End If
        Else
            If OldVal = "" Then
                Target.Value = NewVal
            Else
                ' Delete cell contents
                If NewVal = "" Then
                    Target.Value = ""
                Else

                    ' This IF prevents the same value appearing in the cell multiple times
                    ' If you are happy to have the same value multiple times remove this IF
                    If InStr(Target.Value, NewVal) = 0 Then
                        Target.Value = OldVal & ", " & NewVal
                    End If
                End If
            End If
        End If
        Application.EnableEvents = True   
    Else
        Exit Sub 
    End If
End Sub

我在堆栈溢出中搜索并发现了类似的问题，但是由于我仍然是初学者，我不确定代码必须如何选择“我的活动工作表”