VBA App Crashes w/o Error Message - Works when stepping through program - vba

Question

I have an excel application that often, but not always crashes, when run normally. In case you set a breakpoint and step through the program, it never fails. Likewise if you set breakpoints at strategic places, and then continues executing it generally also works well.
The issue appears to be related to opening a file, copying a large amount of data, and then closing the file. I am however unsure where the program actually crashes. Tips for debugging / methods for finding where the error occurs in the code would be most appreciated.
I have assumed this is due to either a race condition or memory problems, but unsure exactly what would cause either of those errors. Race condition seems more likely though, as pausing or stepping through application shouldn't help with memory issues. If race condition is the cause of the problem, is there a better solution than letting the application sleep/wait at certain points? How do I identify the points where I would need to sleep/wait?
EDIT: When running the application normally it seems to run longer than you would expect, then just closes without any error message. I am running Excel 2013 (32bit) on Win 10.
I considered data being saved to cliboard being the issue, and added
Application.CutCopyMode = False
after each paste, this did not resolve the issue though.
I am supressing alerts and screen updating, i.e.
Application.DisplayAlerts = False
Application.ScreenUpdating = False
but commenting out these settings, still causes application to crash.
EDIT2: Adding the code where the crash occurs. Errors appears to occur somewhere in ReadInAndCopyFiles.
Sub ReadInFiles(wb As Workbook, FolderPath As String, FileName As String)
Dim CurrentWeekDate As Date
Dim TempDate As Date
Dim TempFilePath As String
Dim DataFileName As String
Dim OpenDialog As Office.FileDialog
Dim DateString As String
Dim SheetNameArray As Variant
'Initialization
CurrentWeekDate = wb.Worksheets("Config").Range("EndOfWeekDate").Value
ChDir (FolderPath)
If FileName = "Weekly utilization" Then
SheetNameArray = Array("WeeklyUtilization_CW", "WeeklyUtilization_CW-1", "WeeklyUtilization_CW-2", "WeeklyUtilization_CW-3")
Else
SheetNameArray = Array("Charged Hours", "ChargedHours_CW-1", "ChargedHours_CW-2", "ChargedHours_CW-3")
End If
'Current Week
TempFilePath = FolderPath + FileName + ".xlsx"
ReadInAndCopyFile TempFilePath, CStr(SheetNameArray(0)), "Find " & FileName
'Current Week -1
TempDate = DateAdd("d", -7, CurrentWeekDate)
DateString = Format(TempDate, "yy-mm-dd")
TempFilePath = FolderPath + "Archives\" + FileName + " " + DateString + ".xlsx"
ReadInAndCopyFile TempFilePath, CStr(SheetNameArray(1)), "Find " & FileName & " -1"
'Current Week -2
TempDate = DateAdd("d", -14, CurrentWeekDate)
DateString = Format(TempDate, "yy-mm-dd")
TempFilePath = FolderPath + "Archives\" + FileName + " " + DateString + ".xlsx"
ReadInAndCopyFile TempFilePath, CStr(SheetNameArray(2)), "Find " & FileName & " -2"
'Current Week -3
TempDate = DateAdd("d", -21, CurrentWeekDate)
DateString = Format(TempDate, "yy-mm-dd")
TempFilePath = FolderPath + "Archives\" + FileName + " " + DateString + ".xlsx"
ReadInAndCopyFile TempFilePath, CStr(SheetNameArray(3)), "Find " & FileName & " -3"
End Sub
Sub ReadInAndCopyFile(TempFilePath As String, TargetSheetName As String, CustomMessage As String)
Dim DataFileName As String
Dim SourceWb, wb As Workbook
Dim ws As Worksheet
Dim LastRow, LastColumn, StartRow, TargetLastRow As Variant
Dim OpenDialog As Office.FileDialog
Set wb = ActiveWorkbook
DataFileName = Dir(TempFilePath)
If Not DataFileName <> "" Then
MsgBox CustomMessage
Set OpenDialog = Application.FileDialog(msoFileDialogFilePicker)
OpenDialog.Filters.Clear
OpenDialog.Filters.Add "Excel Files", "*.xlsx"
OpenDialog.AllowMultiSelect = False
OpenDialog.Show
TempFilePath = OpenDialog.SelectedItems(1)
End If
Workbooks.Open FileName:=TempFilePath, UpdateLinks:=False
Set SourceWb = ActiveWorkbook
'Determine where to start pasting, and if header should be included or not
If (wb.Worksheets(TargetSheetName).Cells(Rows.Count, 1).End(xlUp).Row = 1) Then
StartRow = 1
Else
StartRow = wb.Worksheets(TargetSheetName).Cells(Rows.Count, 1).End(xlUp).Row + 1
End If
'Copy First Sheet
LastRow = SourceWb.Worksheets("Sheet1").Cells(Rows.Count, 1).End(xlUp).Row
'Dont copy any data if blank
If LastRow <> 1 Then
LastColumn = SourceWb.Worksheets("Sheet1").Cells(1, Columns.Count).End(xlToLeft).Column
If StartRow = 1 Then
Range(SourceWb.Worksheets("Sheet1").Cells(1, 1), SourceWb.Worksheets("Sheet1").Cells(LastRow, LastColumn)).Copy
Else
Range(SourceWb.Worksheets("Sheet1").Cells(2, 1), SourceWb.Worksheets("Sheet1").Cells(LastRow, LastColumn)).Copy
End If
wb.Worksheets(TargetSheetName).Range("A" + CStr(StartRow)).PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks:=False, Transpose:=False
Application.CutCopyMode = False
TargetLastRow = wb.Worksheets(TargetSheetName).Cells(Rows.Count, 1).End(xlUp).Row
End If
'Copy Second Sheet
LastRow = SourceWb.Worksheets("Sheet2").Cells(Rows.Count, 1).End(xlUp).Row
'Dont copy any data if blank
If LastRow <> 1 Then
LastColumn = SourceWb.Worksheets("Sheet2").Cells(1, Columns.Count).End(xlToLeft).Column
'Copy from row 2 to avoid copying headers again
Range(SourceWb.Worksheets("Sheet2").Cells(2, 1), SourceWb.Worksheets("Sheet2").Cells(LastRow, LastColumn)).Copy
wb.Worksheets(TargetSheetName).Range("A" + CStr(TargetLastRow + 1)).PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks:=False, Transpose:=False
Application.CutCopyMode = False
End If
SourceWb.Close SaveChanges:=False
End Sub

Answer 1

I suspect this bit
Dim OpenDialog As Office.FileDialog
Set wb = ActiveWorkbook
DataFileName = Dir(TempFilePath)
If Not DataFileName <> "" Then
MsgBox CustomMessage
Set OpenDialog = Application.FileDialog(msoFileDialogFilePicker)
OpenDialog.Filters.Clear
OpenDialog.Filters.Add "Excel Files", "*.xlsx"
OpenDialog.AllowMultiSelect = False
OpenDialog.Show
TempFilePath = OpenDialog.SelectedItems(1)
End If
Replace with this
Dim s
Set wb = ActiveWorkbook
datafilename = Dir(tempfilepath)
If datafilename = "" Then
s = Application.GetOpenFilename("*.xlsx,Excel Files", 1, "Select File", , False)
If Not s = False Then
tempfilepath = s
End If
End If

Answer 2

I wasa able to resolve the issue by adding Application.Wait in two places in the code for the sub ReadInAndCopyFile.
'Firstplace
Workbooks.Open FileName:=TempFilePath, UpdateLinks:=False
Application.Wait (Now + TimeValue("0:00:10"))
Set SourceWb = ActiveWorkbook
'Second place
Application.Wait (Now + TimeValue("0:00:10"))
SourceWb.Close SaveChanges:=False
The placement is only due to where I assumed the errors were occurring. It is entirely possible that only one Wait would be enough, and that a shorter wait would be ok. I may do further experimenting later, but for now it is enough that it is running.
Happy to hear if anyone has better or faster methods for resolving this, as this methods as a significant amount of time to the total running time.