Specific formulas not working in Loop_all_files_in_folder macro

[Nbisgaard]

I have a macro to loop all the files in a folder, which works, and looks like this:

Sub ALLE_FILER_I_MAPPE()Dim wb As Workbook
Dim myPath As String
Dim myFile As String
Dim myExtension As String
Dim FldrPicker As FileDialog

  Application.ScreenUpdating = False
  Application.EnableEvents = False
  Application.Calculation = xlCalculationManual


 Set FldrPicker = Application.FileDialog(msoFileDialogFolderPicker)


    With FldrPicker
      .Title = "Select A Target Folder"
      .AllowMultiSelect = False
        If .Show <> -1 Then GoTo NextCode
        myPath = .SelectedItems(1) & "\"
    End With


NextCode:
  myPath = myPath
  If myPath = "" Then GoTo ResetSettings


  myExtension = "*.xls"


  myFile = Dir(myPath & myExtension)


  Do While myFile <> ""
      Set wb = Workbooks.Open(Filename:=myPath & myFile)

wb.Worksheets(1).Range("D3").Formula = "=[data_til_dokumentation.xlsx]PI!$B$1"

    'Save and Close Workbook
      wb.Close SaveChanges:=True


      myFile = Dir
  Loop


  MsgBox "Task Complete!"


ResetSettings:
    Application.EnableEvents = True
    Application.Calculation = xlCalculationAutomatic
    Application.ScreenUpdating = True


End Sub

If i instead of

wb.Worksheets(1).Range("D3").Formula = "=[data_til_dokumentation.xlsx]PI!$B$1"

input:

wb.Worksheets(1).Range("N10").Formula = "=INDEX([data_til_dokumentation.xlsx]LS!$C$11:$C$18;MATCH(M10;[data_til_dokumentation.xlsx]LS!$B$11:$B$18;0)+0)"

I get an error Run-time error '1004':

I have checked that the formula i input actually do work when i copy paste it manually into the cell in question.

What am i doing wrong?

[Aflatoon]

Replace the semicolons with commas in the formula when using the .Formula property (it expects US notation).