How to fix an error occurring within this VBA function? (ERR91: Obj/With Variable Not Set)

Hi All,

Not sure if this falls in the Word or Excel VBA bucket (I think Excel?). I've been trying to stitch together a Word VBA Script that takes all the Word comments and puts them into a new Excel spreadsheet, then formats the Excel spreadsheet.

However the "Excel" portion of the code seems to fail after every "other" run. Specifically the error occurs when trying to Left-Align Column C. The error that occurs is "Error 91 - Object variable or With block variable not set". The error happens every 2 runs.

Would anyone know how to fix the Error that occurs below, please? Thanks so much in advance!
(The offending/highlighted line below is: ActiveSheet.Columns("C").HorizontalAlignment = xlHAlignLeft )

Function CopyWordCommentstoNewExcelFile()
 'Takes MS Word comments and puts them into an Excel File

  Dim xlApp As Excel.Application
  Dim xlWB As Excel.Workbook
  Dim i As Integer
  Dim HeadingRow As Integer
  HeadingRow = 3

  Dim cmtRef As Range

  Set xlApp = CreateObject("Excel.Application")
  xlApp.Visible = True
  Set xlWB = xlApp.Workbooks.Add ' create a new workbook
  
  With xlWB.Worksheets(1) 'START EXCEL INTEGRATION
    'Create report info
    .Cells(1, 1).Formula = "Reviewed document:"

    'Create Heading
    .Cells(HeadingRow, 1).Formula = "Issue #"
    .Cells(HeadingRow, 2).Formula = "Section #"
    .Cells(HeadingRow, 3).Formula = "Step #"
    .Cells(HeadingRow, 4).Formula = "Issue abstract/comment/resolution:"
    
    Dim strStep, strComment As String
    
    For i = 1 To ActiveDocument.Comments.Count
   
      'ISSUE #
      .Cells(2, 1).Formula = ActiveDocument.Comments(i).Parent
      .Cells(i + HeadingRow, 1).Formula = ActiveDocument.Comments(i).Index 'COL A
        
      'SECTION NUMBER
      strDocSection = ReplaceAndSplit(ActiveDocument.Comments(i).Range, "(,)#")(1)
      .Cells(i + HeadingRow, 2).Formula = strDocSection 'COL B
                
      'STEP NUMBER
      strStempNumber = GetBetween(ActiveDocument.Comments(i).Range, ", #", ")")
      .Cells(i + HeadingRow, 3).Formula = strStempNumber 'COL C
        
      'COMMENT
      strComment = GetBetween(ActiveDocument.Comments(i).Range, ") ", " (")
      .Cells(i + HeadingRow, 4).Formula = strComment 'COL D
           
    Next i
  
  
  '--BEGIN FORMATTING--  'THE PROBLEM HAPPENS WHEN RUNNING THE LEFT-ALIGN CODE BELOW
    
   'LEFT ALIGN COL C
   ActiveSheet.Columns("C").HorizontalAlignment = xlHAlignLeft '<-- THIS FAILS AFTER EVERY-OTHER RUN WITH "ERROR 91 - Object variable or With block variable not set", BUT WORKS ON THE NEXT RUN
  
   '--END FORMATTING--
  
  End With 'END EXCEL INTEGRATION
  
End Function

Thanks so much,
JMC