Difficulty with the worksheetfunction.match property in VBA - vba

Question

I keep getting the error "Run-time error '91': "Object Variable or With block variable not set" when my macro gets to the line
matchrange = Workbooks("tracker test").Sheets(start_sheet).Range("F" & h).Value
where I am trying to define the PLnumber that will be compared to the PL_compare_list named range. If I try to not define that variable and instead just put the reference directly into my match function on the line below I instead get the error "Run-time error '1004': Unable to get the Match property of the WorksheetFunction class"
What I am trying to do is have this code look at column H on start_sheet to see if it has data yet. then, if it does not, compare the PL numbers on start_sheet in column F to the PL numbers on "Calculation Sheet" in column B to find a row and then open the corresponding file name that is in column A in that row. Thoughts?
Here is my code in its entirety but I think the most relevant bits will be close to the bottom:
Option Explicit
Sub GetFileNames()
Range("A1").Select
ActiveCell.FormulaR1C1 = _
"=REPLACE(CELL(""filename""),FIND(""["",CELL(""filename"")),LEN(CELL(""filename"")),MID(CELL(""filename""),FIND(""]"",CELL(""filename""),1)+1,255))&""_samples shipment PO_PL_Invoice_ attachment\""&TRIM(MID(CELL(""filename""),FIND(""]"",CELL(""filename""),1)+1,255))&""_PL\"""
Range("B1").Select
ActiveCell.FormulaR1C1 = _
"=left(RC[-1],len(RC[-1])-10)"
Range("A1:B1").Select
Application.CutCopyMode = False
Selection.Copy
Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
:=False, Transpose:=False
Dim directory As String
directory = Range("B1").Value
Dim start_sheet As String
start_sheet = ActiveSheet.Name
Sheets("Calculation Sheet").Activate
Range("D1") = Sheets(start_sheet).Range("A1").Value
Columns("B:B").Select
Application.CutCopyMode = False
Selection.ClearContents
ActiveSheet.Cells(1, 1).Select
Dim xRow As Long
Dim xDirect$, xFname$, InitialFoldr$
InitialFoldr$ = directory
With Application.FileDialog(msoFileDialogFolderPicker)
.InitialFileName = Application.DefaultFilePath & "\"
.Title = "Please select a folder to list Files from"
.InitialFileName = InitialFoldr$
.Show
If .SelectedItems.Count <> 0 Then
xDirect$ = .SelectedItems(1) & "\"
xFname$ = Dir(xDirect$, 7)
Do While xFname$ <> ""
ActiveCell.Offset(xRow) = xFname$
xRow = xRow + 1
xFname$ = Dir
Loop
End If
End With
Dim i As Integer
Dim j As Integer
Dim filenumber As Integer
filenumber = Evaluate("CountA(A:A)")
Columns("A:A").Select
Selection.NumberFormat = "#"
j = 1
For i = 1 To filenumber
If InStr(1, Range("A" & i), "xlsx") Then
ActiveSheet.Range("B" & j).Value = ActiveSheet.Range("D1").Value & ActiveSheet.Range("A" & i).Value
j = j + 1
End If
Next i
Columns("B:B").Select
Selection.Copy
Columns("A:A").Select
Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
:=False, Transpose:=False
Columns("B:E").Select
Application.CutCopyMode = False
Selection.ClearContents
Dim xlfilenumber As Integer
Dim PL_list_length As Integer
xlfilenumber = Evaluate("CountA(A:A)")
ActiveSheet.Range("A1:A" & xlfilenumber).Select
Selection.Name = "list_of_files"
For i = 1 To xlfilenumber
Range("B" & i).Select
ActiveCell.FormulaR1C1 = _
"=MID(RC[-1],FIND(""_PL"",RC[-1],FIND(""_PL\"",RC[-1],1)+4)+1,7)"
Next i
xlfilenumber = Evaluate("CountA(B:B)")
ActiveSheet.Range("A1:A" & xlfilenumber).Select
Selection.Name = "PL_compare_list"
Sheets(start_sheet).Activate
PL_list_length = Evaluate("CountA(F:F)") - 1
Dim h As Integer
Dim g As Integer
Dim filerownum As Integer
Dim matchrange As Range
Dim comparerange As Range
Dim filename As String
For h = 6 To 9
If IsEmpty(Range("J" & h)) Then
matchrange = Workbooks("tracker test").Sheets(start_sheet).Range("F" & h).Value
filerownum = Application.WorksheetFunction.Match(matchrange, Worksheets("Calculation Sheet").Range("PL_compare_list"), 0)
filename = Range("A" & filerownum).Value
Workbooks.Open filename
End If
Next h
Workbooks("tracker test").Sheets(start_sheet).Activate
If (ActiveSheet.AutoFilterMode And ActiveSheet.FilterMode) Or ActiveSheet.FilterMode Then
ActiveSheet.ShowAllData
End If
ActiveSheet.Cells(1, 1).Select
Application.CutCopyMode = False
Selection.ClearContents
ActiveSheet.Cells(1, 2).Select
Application.CutCopyMode = False
Selection.ClearContents
ActiveSheet.Cells(1, 3).Select
Application.CutCopyMode = False
Selection.ClearContents
End Sub

Answer 1

Ideally there's a bunch of other changes you should consider, but to address the question of how to handle a failed Match:
Dim filerownum As Variant
Dim rngSrch As Range
Set rngSrch = Worksheets("Calculation Sheet").Range("PL_compare_list")
For h = 6 To 9
If IsEmpty(Range("J" & h)) Then
matchrange = Workbooks("tracker test").Sheets(start_sheet).Range("F" & h).Value
'drop the WorksheetFunction
filerownum = Application.Match(matchrange, rngSrch, 0)
'test for error return value
If Not IsError(filerownum) Then
filename = Range("A" & filerownum).Value
Workbooks.Open filename
End If
End If
Next h