mail merge - cannot run as document is not open

[Mike2502]

Hi All,

I'm trying to run my mailmerge but an error keeps coming up

'This command is not available because no document is open' on the line below

ActiveDocument.MailMerge.MainDocumentType = wdFormLetters

Whole Code

Application.ScreenUpdating = False
Dim StrFolder As String, StrName As String, MainDoc As Document, i As Long, j As Long
Const StrNoChr As String = """*./\:?|"
Dim MyDate
Dim Month

MyDate = Format(Date, "yyyymmdd")
Month = Format(Date, "mmmm")

    ActiveDocument.MailMerge.MainDocumentType = wdFormLetters
    ActiveDocument.MailMerge.OpenDataSource Name:="location.xlsm" _
        , ConfirmConversions:=False, ReadOnly:=False, LinkToSource:=True, _
        AddToRecentFiles:=False, _
        WritePasswordDocument:="", Revert:=False, _
        Format:=wdOpenFormatAuto, Connection:= _
        "Provider=Microsoft.ACE.OLEDB.12.0;User ID=Admin;Data Source=Location.xlsm;Mode=Read;Extended Properties=""HDR=YES;IMEX=1;"";Jet OLEDB:System database="""";Jet OLEDB:Registry Path="""";Jet OLEDB" _
        , SQLStatement:="SELECT * FROM `Sheet1$`", SQLStatement1:="", SubType:= _
        wdMergeSubTypeAccess
        
Set MainDoc = ActiveDocument
With MainDoc
  StrFolder = "Location" & Month & "\"
  With .MailMerge
    .Destination = wdSendToNewDocument
    .SuppressBlankLines = True
    On Error Resume Next
    For i = 1 To .DataSource.RecordCount
      With .DataSource
        .FirstRecord = i
        .LastRecord = i
        .ActiveRecord = i
        If Trim(.DataFields("Payroll_No")) = "" Then Exit For
        'StrFolder = .DataFields("Folder") & "\"
        StrName = MyDate & " - " & .DataFields("Employee_Name") ""
      End With
      .Execute Pause:=False
      If Err.Number = 5631 Then
        Err.Clear
        GoTo NextRecord
      End If
      For j = 1 To Len(StrNoChr)
        StrName = Replace(StrName, Mid(StrNoChr, j, 1), "_")
      Next
      StrName = Trim(StrName)
      With ActiveDocument
        .SaveAs FileName:=StrFolder & StrName & ".docx", FileFormat:=wdFormatXMLDocument, AddToRecentFiles:=False
        ' and/or:
        .SaveAs FileName:=StrFolder & StrName & ".pdf", FileFormat:=wdFormatPDF, AddToRecentFiles:=False
        .Close SaveChanges:=False
      End With
NextRecord:
    Next i
  End With
End With
Application.ScreenUpdating = True
ActiveDocument.Close SaveChanges:=wdDoNotSaveChanges
End Sub