Excel Sheet Name Error - vba

Question

I'm using a VBA code to cycle through excel files in a directory and pull information from one worksheet and paste into a newly created worksheet. I'm also naming my new worksheets (in my destination file) by the name in one of the cells in the source file.
My code works for the first loop but fails/stops in the second loop (VBA points to an error in the Dest.Sheets.Add(After:=Dest.Sheets(Dest.Sheets.Count)).Name = Sheetname line. I need to loop through 75 of these files and I'm unsure of what's going on because it works correctly for the first file.
Thanks so much for the help!
Sub AddSummaryTables()
Dim Spath, Filename, Sheetname As String
Dim Source, Dest As Workbook
Dim WS As Worksheet
Set Dest = ThisWorkbook
Spath = InputBox("Enter File Source Path") & "\"
Filename = Dir(Spath & "*.xls*")
Do While Filename <> ""
Set Source = Workbooks.Open(Spath & Filename)
Sheetname = Source.Sheets("Summary").Range("B2").Text
MsgBox Sheetname
Dest.Sheets.Add(After:=Dest.Sheets(Dest.Sheets.Count)).Name = Sheetname
Source.Sheets("Summary").Range("A1:R150").Copy
Dest.Worksheets(Sheetname).Range("A1").PasteSpecial xlPasteValues
Dest.Worksheets(Sheetname).Range("A1").PasteSpecial xlPasteFormats
Dest.Worksheets(Sheetname).Range("A1:R150").WrapText = False
Dest.Worksheets(Sheetname).Rows.AutoFit
Dest.Worksheets(Sheetname).Columns.AutoFit
Source.Close SaveChanges:=False
Dest.Save
Filename = Dir()
Loop
End Sub

Answer 1

following Comintern's and Wyatt's suggestion you could try like follows
Option Explicit
Sub AddSummaryTables()
Dim sPath As String, fileName As String
Dim sourceWb As Workbook, destWb As Workbook
Dim sourceWs As Worksheet, destWs As Worksheet
Set destWb = ThisWorkbook
sPath = InputBox("Enter File Source Path") & "\"
fileName = Dir(sPath & "*.xls*")
Do While fileName <> ""
Set sourceWb = Workbooks.Open(sPath & fileName)
Set sourceWs = GetWorksheet(sourceWb, "Summary")
If Not sourceWs Is Nothing Then
Set destWs = SetWorksheet(destWb, sourceWs.Range("B2").Text)
sourceWs.Range("A1:R150").Copy
With destWs
.Range("A1").PasteSpecial xlPasteValues
.Range("A1").PasteSpecial xlPasteFormats
.UsedRange.WrapText = False
.Rows.AutoFit
.Columns.AutoFit
End With
sourceWb.Close SaveChanges:=False
destWb.Save
End If
fileName = Dir()
Loop
End Sub
Function GetWorksheet(wb As Workbook, sheetName As String) As Worksheet
On Error Resume Next
Set GetWorksheet = wb.Worksheets(sheetName)
On Error GoTo 0
End Function
Function SetWorksheet(wb As Workbook, sheetName As String) As Worksheet
Dim i As Integer
Do While Not GetWorksheet(wb, sheetName & IIf(i = 0, "", "-" & i)) Is Nothing
i = i + 1
Loop
With wb
.Worksheets.Add(After:=.Worksheets(.Worksheets.Count)).Name = sheetName & IIf(i = 0, "", "-" & Format(i, "000"))
Set SetWorksheet = .ActiveSheet
End With
End Function
where you make sure that
any opened workbook has a "Summary" worksheet
you name worksheets in your destination workbook such as not to have duplicates: if you happen to deal with say three worksheets named "Sheet5" then your destination workbook will have added worksheets "Sheet5", "Sheet5-001" and "Sheet5-002".

Answer 2

You're issue may be that when you are adding the sheet from the second workbook, it has the same name as the sheet from the first workbook. You could check if the sheet exists and add a number to it. The post below might help.
Test or check if sheet exists