Macro breaks when ran for the first time of the day - excel

Question

When I run my macro for the first time for the day it fails when it adds another sheet to the file.
Run-time error 1004: That name is already taken. Try a different
one.
My goal:
look for the file within \Downloads
convert the saved file it found from .xls -> .xlsx
delete the original downloaded file
run a bunch of formatting for printing.
When it fails, I close the current file, re-download the file, manually save the file with the needed format & name, delete the download, re-download the file.
After that I can run the macro.
The line that breaks: Sheets.Add(After:=Sheets("Dock Activity Report")).Name = "Cases"
Sub Schedule_macro()
Dim Filename, Pathname, SaveFileName As String
Dim wb As Workbook
Dim UserName As String
UserName = Environ("username")
Pathname = "C:\Users\" & Environ$("username") & "\Downloads\"
Filename = Dir(Pathname & "Dock_Activity_*.xls")
SaveFileName = Dir(Pathname & "dockactivity.xlsx")
Application.DisplayAlerts = False
If Len(Dir(Pathname & "Dock_Activity_*.xls")) > 0 Then
Debug.Print "Filename found, running macro"
Else
MsgBox "You need to download the" & vbNewLine & "Dock Activity Report from the" & vbNewLine & "'Report Run Log' in Lean." & vbNewLine & vbNewLine & "Once downloaded, please rerun the macro", vbCritical, "HiRise Schedule Macro"
Debug.Print "could not find Filename within given Pathname"
Debug.Print "exiting macro"
Exit Sub
End If
Do While Filename <> ""
Set wb = Workbooks.Open(Pathname & Filename)
wb.CheckCompatibility = True
Application.DisplayAlerts = False
wb.SaveAs Filename:="dockactivity", FileFormat:=xlOpenXMLWorkbook
wb.Close SaveChanges:=False
Filename = Dir(Pathname & "Dock_Activity_*.xls")
Filename = Dir()
Loop
Application.DisplayAlerts = True
If Dir(Pathname & "Dock_Activity_*.xls") <> "" Then
kill (Pathname & "Dock_Activity_*.xls")
End If
Debug.Print "looking for SaveFileName within given Pathname"
Set wb = Workbooks.Open(Pathname & "dockactivity.xlsx")
Debug.Print "SaveFileName found, opening file"
Windows("dockactivity.xlsx").Activate
Rows("1:21").Delete Shift:=xlUp
Range("A:B,D:F,H:N,S:S,U:V,X:Y,AB:AK,AM:BA").Delete Shift:=xlToLeft
Columns("H:H").Cut
Columns("A:A").Insert Shift:=xlToRight
Columns("K:K").Cut
Columns("G:G").Insert Shift:=xlToRight
Columns("J:K").Copy
Range("L1").Select
ActiveSheet.Paste
Application.CutCopyMode = False
Columns("J:K").ClearContents
Range("J1").FormulaR1C1 = "Trailer Number"
Range("K1").FormulaR1C1 = "Arrival Time"
Columns("G:M").Copy
Range("N1").Select
ActiveSheet.Paste
Application.CutCopyMode = False
Selection.ClearContents
Range("N1").FormulaR1C1 = "Door"
Range("O1").FormulaR1C1 = "Ship Rail"
Range("P1").FormulaR1C1 = "Staged"
Range("Q1").FormulaR1C1 = "Check If Loaded"
Range("R1").FormulaR1C1 = "Case Picks"
Range("S1").FormulaR1C1 = "Layer Picks"
Range("T1").FormulaR1C1 = "Check if Released by Pool"
Debug.Print "1:1 table headers complete"
Columns("A:B").ColumnWidth = 17.71
Columns("C:C").ColumnWidth = 19.14
Columns("D:D").ColumnWidth = 25.71
Columns("E:E").ColumnWidth = 14.41
Columns("F:F").ColumnWidth = 10.71
Columns("G:G").ColumnWidth = 30.29
Columns("H:H").ColumnWidth = 9.43
Columns("I:I").ColumnWidth = 13.71
Columns("J:J").ColumnWidth = 26.14
Columns("K:L").ColumnWidth = 23.57
Columns("M:M").ColumnWidth = 46
Columns("N:S").ColumnWidth = 15
Columns("T:T").ColumnWidth = 12.86
Debug.Print "column resizing complete"
Cells.Select
With Selection.Font
.Name = "Arial"
.Size = 14
.Strikethrough = False
.Superscript = False
.Subscript = False
.OutlineFont = False
.Shadow = False
.Underline = xlUnderlineStyleNone
.TintAndShade = 0
.ThemeFont = xlThemeFontNone
End With
Rows("1:1").RowHeight = 75
Rows("2:150").RowHeight = 55
' #############################################################################
Sheets.Add(After:=Sheets("Dock Activity Report")).Name = "Cases"
Sheets.Add(After:=Sheets("Cases")).Name = "Layers"
' #############################################################################
Sheets("Dock Activity Report").Range("R2:R150").FormulaR1C1 = "=VLOOKUP(RC[-17],Cases!C[-13]:C[-12],2,FALSE)"
Sheets("Dock Activity Report").Range("S2:S150").FormulaR1C1 = "=VLOOKUP(RC[-18],Layers!C[-15]:C[-14],2,FALSE)"
Worksheets("Dock Activity Report").Select
Range("A2:T150").Select
Selection.FormatConditions.Add Type:=xlExpression, Formula1:= _
"=$C2=""Live Trailer"""
Selection.FormatConditions(Selection.FormatConditions.Count).SetFirstPriority
With Selection.FormatConditions(1).Interior
.PatternColorIndex = xlAutomatic
.Color = 65535
.TintAndShade = 0
End With
Range("B2:B150").Select
ActiveWorkbook.Worksheets("Dock Activity Report").Sort.SortFields.Clear
ActiveWorkbook.Worksheets("Dock Activity Report").Sort.SortFields.Add Key:= _
Range("B2"), SortOn:=xlSortOnValues, Order:=xlAscending, DataOption:= _
xlSortNormal
With ActiveWorkbook.Worksheets("Dock Activity Report").Sort
.SetRange Range("A1:T150")
.Header = xlGuess
.MatchCase = False
.Orientation = xlTopToBottom
.SortMethod = xlPinYin
.Apply
End With
ActiveWorkbook.Worksheets("Dock Activity Report").Select
Columns("A:A").Copy
Columns("B:B").Insert Shift:=xlToRight
Range("B2").Select
Application.CutCopyMode = False
ActiveCell.FormulaR1C1 = "=IFERROR(RC[-1]*1,TRIM(RC[-1]))"
Range("B3").Select
Range("B2").Select
Selection.AutoFill Destination:=Range("B2:B150"), Type:=xlFillDefault
Range("B2:B150").Select
Columns("B:B").Copy
Range("A1").PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
:=False, Transpose:=False
Columns("B:B").Select
Application.CutCopyMode = False
Selection.Delete Shift:=xlToLeft
Debug.Print "A:A value reformat complete"
Sheets("Dock Activity Report").Select
Columns("A:T").Select
Selection.FormatConditions.Add Type:=xlExpression, Formula1:= _
"=COUNTA($A1:$F1)>0"
Selection.FormatConditions(Selection.FormatConditions.Count).SetFirstPriority
With Selection.FormatConditions(1).Borders
.LineStyle = xlContinuous
.TintAndShade = 0
.Weight = xlThin
End With
Selection.FormatConditions(1).StopIfTrue = False
Debug.Print "cell borders added"
Dim r As Long
Dim LastRow As Long
LastRow = Cells(Rows.Count, "A").End(xlUp).Row
For r = LastRow To 1 Step -1
If Cells(r, 1) = 0 Then
Rows(r).Delete
End If
Next r
Range("A1").Select
Sheets("Cases").Range("E2:E300").FormulaR1C1 = "=VALUE(TRIM(CLEAN(RC[-4])))"
Sheets("Cases").Range("F2:F300").FormulaR1C1 = "=RC[-2]"
Sheets("Cases").Columns("E:F").EntireColumn.Hidden = True
Sheets("Layers").Range("D2:D300").FormulaR1C1 = "=VALUE(TRIM(CLEAN(RC[-3])))"
Sheets("Layers").Range("E2:E300").FormulaR1C1 = "=RC[-2]"
Sheets("Layers").Columns("D:E").EntireColumn.Hidden = True
Sheets("Dock Activity Report").Range("A1").Select
Application.DisplayAlerts = False
ActiveWorkbook.Save
Application.DisplayAlerts = True
MsgBox "All Finished!", vbInformation, "HiRise Schedule"
ActiveWorkbook.Save
End Sub

Answer 1

That is because there is already a sheet with that name.
Add this code and it will be ok.
On Error Resume Next
Application.DisplayAlerts = False
Sheets("Cases").Delete
Application.DisplayAlerts = True
On Error GoTo 0
Sheets.Add(After:=Sheets("Dock Activity Report")).Name = "Cases"
TIP: Avoid the use of .Select/Activate. Work with Objects. You may want to see How to avoid using Select in Excel VBA. It will be easy to manage the code as well.