运行时错误“ 5”：第二秒= Dir时参数无效

Question

我在编写代码时遇到问题，我知道它并不完美并且非常敏捷，但是我仍在学习整个vba知识。我遇到的问题是当我循环并转到第二个=dir

时

Sub LoopThroughFiles()
    Dim StrFolder As Variant
    Dim StrFile As String




    StrFolder = "C:\temp\output\"
    StrFile = Dir("C:\temp\output\")
    Do While Len(StrFile) > 0
    Set wb = Workbooks.Open(Filename:=StrFolder & StrFile)
        strSearch = "2675"

    Set ws = Worksheets("TestCases")


    With ws
        Set aCell = .Columns(3).Find(What:=strSearch, LookIn:=xlValues, _
        LookAt:=xlWhole, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
        MatchCase:=False, SearchFormat:=False)

         If Not aCell Is Nothing Then
            Set bcell = aCell

                Columns("E:E").Insert
            aCell.Offset(0, 2) = "FD/WagesAmt"
            strSearch = Dir
    End If
    End With

            strSearch = "2017"
                Set ws = Worksheets("TestCases")
                With ws
                Set aCell = .Columns(3).Find(What:=strSearch, LookIn:=xlValues, _
                LookAt:=xlWhole, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
                MatchCase:=False, SearchFormat:=False)

                If Not aCell Is Nothing Then
                Set bcell = aCell

                aCell.Offset(0, 2) = "FD/Amt"
                aCell.Offset(5, 2) = "FD/Amt"
                strSearch = Dir

        End If
    End With
     strSearch = "2078"
                Set ws = Worksheets("TestCases")

                With ws
                Set aCell = .Columns(3).Find(What:=strSearch, LookIn:=xlValues, _
                LookAt:=xlWhole, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
                MatchCase:=False, SearchFormat:=False)

                If Not aCell Is Nothing Then
                Set bcell = aCell
                aCell.Offset(0, 2) = "FD/mt"
                aCell.Offset(5, 2) = "FD/mt"
                    ActiveWorkbook.Close SaveChanges:=True
                    Application.DisplayAlerts = True
                    Application.ScreenUpdating = True
                strSearch = Dir

        End If
     StrFile = Dir

    End With


        StrFile = Dir
    Loop
End Sub

当它完成第一个循环并转到下一个循环时，strSearch = Dir会返回运行时错误，我不确定为什么会这样。任何帮助都非常感谢