Modeless Userform not terminating

One way to display status messages as a long procedure runs is to show a modeless userform and update it with text or a progress bar showing percentage completed.
I was having a problem with Excel crashing, particularly Excel 2013, and I traced it to a userform like that. Here is a sample:

Run the ShowProblem sub.
1. With the button visible, there is no problem. The userform is terminated when the oFrm variable goes out of scope after the form is Hidden.

2. With the button not visible, the form terminate event does not fire. The userform is left in memory, (iow it is not removed by the garbage collector) and its window can be seen by WinSpy++ (class ThunderDFrame) but it is no longer accessible because its object pointer has gone out of scope.
In the addin I was working with, after a number of such windows accumulate, and in Excel 2013 they are owned by a workbook rather than the main Excel window, Excel crashes when the workbook is closed and the windows start to terminate one after the other.

3. In the demo file, run the sub twice in a row, now two ThunderDFrame windows appear in WinSpy++, and an orphaned Excel process is left behind with no App window.

The way to avoid that is to use an explicit Unload command which is better practice anyway than relying on the combination of .Hide and letting oFrm go out of scope.
According to Rory Archibald, “[it] stems from not having any controls on the form that can take focus.”
It’s the kind of thing that wastes hours of debugging.


In previous versions of Excel, forms were always owned by the Excel main window (XLMAIN). Excel 2013 introduced SDI so now forms are owned by the last opened document window so we have to resort to API kludges to change the owner, like this helpful contribution from Jan Karel Pieterse:

MSDN: Window Features, definitions of Owner and Parent

Note: GWL_HWNDPARENT changes the OWNER, not the parent, of a window

Greg Maxey’s MS Word page: Userform – Advanced Notes and Tips

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VBA Code Tracer / Profiler

Simple VBA code tracing

To track down a problem with Excel crashing I needed to get a debug trace of every procedure so I could find which one was causing the crash and I could then single step through it with F8. The simplest method I found was to insert a line at the top of every procedure which initialises an object from a user-defined class.  There is a Start method to set the proc name as we can’t pass that to the class Initialize event. The inserted line to create an object variable named P_ looks like this, immediately after each Sub or Function declaration:

Sub MyProc(param1 as long,etc)
Dim P_ As New Profiler: P_.Start "MyProc"

When this object goes out of scope when the sub exits, its Terminate event is called to record the exit. The class methods simply OutputDebugString the procedure name and a 1 for a start or -1 for the exit. I use OutputDebugString because I can see what the output is in DebugView whereas with Debug.Print the immediate window is lost when Excel crashes. I could write to a text file but the need to close and reopen it every time is slower than DebugView which itself adds quite an overhead.
I have also developed the idea to add a tracing line to each numbered line of code to be able to track in greater detail, particularly when there are long loops where F8 is a tedious way to find the point of a crash. If there is interest, I may post that too.

Here is the VBA code to inject the tracing calls. Copy and paste the code into a standard module and add a reference in the VBA Editor to Microsoft Visual Basic for Applications Extensibility 5.3.                  (Updated 8-Apr-16)

It outputs lines to DebugView which you can then save to a file. The lines look like:

00005595 17883.11132813 ,Module1.MyProc,1
00005596 17883.23456789 ,Module1.MyProc,-1
The first number is the DebugView sequence number, the next after a tab character is the time. The procedure name is prefixed by the module name, as there can be several procedures (especially event procedures) with the same name. The 1 marks the start of the proc and the -1 is the exit. You can analyse that data to see which procedure is called most often, or takes the longest.


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Excel Options for updating external links

There are many options in Excel that control this depending on the kind of link it is. I’ll cover the usual external links in formulas first, then finish up with the other kinds.

An external link formula shows the full path to the source if that workbook is closed, otherwise it shows only the workbook name in the path. For more information, see the MS article ‘Create an external reference (link) to a cell range in another workbook


You can link to cell addresses or names; obviously named ranges are safer because addresses can be affected by insertions or deletions in the source worksheet. To find where links are used in a workbook, search in formulas for “.xl*!”; that is, an Excel file name followed by an exclamation mark.

As well as intentionally created links you enter in formulas, links can be created by Excel when you copy sheets from one workbook to another, and those sheets contain references to other sheets either obviously in formulas or less obviously in range names. If you get a prompt to update links when you open a workbook, but you cannot find any cells containing links, the link is probably in a name. Use the Name Manager (either Excel’s own or the free third-party JKP Name Manager ) to check all names for links, particularly phantom links which are not used but clutter up the list.

To control whether values are updated when the workbook containing the links (the ‘target’ workbook) is opened, use the Edit Links button in the Data tab of the Ribbon. Click the ‘Startup Prompt’ button, and select one of these three:

1: Let users choose to display the alert or not

Now, what happens at startup depends on another setting:

Options > Advanced > General: Ask to update automatic links.  (VBA: Application.AskToUpdateLinks). If true, the user is alerted and can choose whether to update or not. If false, the links are updated.

2: Don’t display the alert and don’t update automatic links

Links are not updated at startup, regardless of the setting of Application.AskToUpdateLinks.

3: Don’t display the alert and update links

Links are updated at startup, regardless of the setting of Application.AskToUpdateLinks.

In VBA, ThisWorkbook.UpdateLinks has the values 1,2, or 3 above.


If the source workbooks are open at the same time as the target, the formulas are part of the recalculation chain as normal. The link values from closed files are not refreshed in a recalculation. Excel provides no way to automatically refresh the values of external link formulas to CLOSED workbooks. To manually update values at any time while using a workbook, use Edit Links, and for each link click ‘Update Values’. You can add a macro that calls ActiveWorkbook.UpdateLink. To update all links, pass it the array of link sources as follows:

ActiveWorkbook.UpdateLink _

If you omit the parameter, by default Excel uses xlLinkTypeExcelLinks. The other type of XlLInkType is xlLinkTypeOLELinks, see below for those.

If any links are bad, that raises an error. To update them one by one and trap the error:

Sub UpdateAllLinks()
   UpdateLinks xlLinkTypeExcelLinks
   UpdateLinks xlLinkTypeOLELinks
End Sub

Sub UpdateLinks(LinkType As XlLinkType)
Dim vSource As Variant
Application.DisplayAlerts = False ' comment out to see the prompt for missing link sources
For Each vSource In ActiveWorkbook.LinkSources(LinkType)
   On Error Resume Next
   Debug.Print vSource
   Application.DisplayAlerts = False
   ActiveWorkbook.UpdateLink Name:=vSource, Type:=LinkType
   If Err <> 0 Then
      Debug.Print "^Error "; Err; Err.Description
   End If
Next vSource
Application.DisplayAlerts = True
End Sub

You could call that macro in the Worksheet_Calculate event to update link values every time a recalculation happens. That will slow down performance, particularly for links over a network rather than to local drives.

To automate the calling of this macro at regular intervals, you can use the .Ontime method. Again, be aware when you do this of the length of time it takes to update the values.

In the ThisWorkbook class module:


Sub Workbook_Open()
      Auto_UpdateExcel Links
End Sub

In a standard module:

Sub Auto_UpdateExcelLinks()
      Application.OnTime DateAdd("s",10,Now()), "Auto_UpdateExcelLinks")
End Sub


Other ways to link to external data

OLE: Object Linking and Embedding can be used for other Office applications such as linking Word or PowerPoint to Excel. You could link Excel to Word if you like, odd though it looks. Copy the data in Word then in Excel Paste Special, Link, and select the format you want. ‘HTML’ suits Word tables, ‘Microsoft Word Document Object’ inserts an object with the formatting as in Word.

The Edit Links dialog allows you to choose Automatic or Manual update only for OLE links. Excel links always have the Manual option button greyed out. If it is automatic then it is refreshed live in Excel as soon as the source document is changed, even without saving the document. If it is manual then it can be updated through Edit Links, select the link, click Update Values.

The Excel setting ‘Options > Advanced > When calculating this workbook: Update links to other documents’ controls the updating of OLE links only. (VBA: ThisWorkbook.UpdateRemoteReferences ) When unchecked, OLE links do not update, even if you select ‘Update Values’ in the Edit Links dialog for that link.


Connections: set up by the Get External Data button. These create queries which are refreshed by the Refresh button. You can link to text files (eg CSV), other workbooks, databases, and web pages.  For further details see MS support and many other websites:


RTD / DDE: Real Time Data and Dynamic Data Exchange. These are ways of getting data from COM instances on a server. For more information, see MS support and the Wilmott forums.


Macros: Data can be read and written by VBA code with Workbooks.Open, Querytables, ADO and SQL. Worksheet shapes can contain links to macros in other workbooks, so clicking them may cause Excel to attempt to open those other workbooks.


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A first look at the FUSE spreadsheet corpus

Following on the first paper by Titus Barik et al
and some work by Mark Townsend analysing the last row and column used in each file

I downloaded the 7GB of 249,376 files and did some summary analysis of them and the VBA.

The top domain is .org (29.5%),followed by .gov (27.7%)
That’s because almost half the files are from one web site – They look like files that were filled in for reporting purposes, and so contain no formulas.
Files which are simple web report downloads or automatically generated (eg then they were not user-created spreadsheets at all, and so of no interest to me.
5,600 have “SpreadsheetGear” as a write access user, all from

So most of the FUSE spreadsheets are of no interest to me in formula error research.
There are no .xlsm files although a simple google finds 106,000.

Of the 5037 web hosts, accounts for 106328 files, or 43% of the total. 106328 47025 10350
The top 3 account for 66% of the files, the top 50 (1% of the hosts) have 87% of the files.
So it’s pretty skewed towards a few domains.

The POI analysis can not handle Biff5 files, but they can be processed in Excel if you relax the File Block settings.
The top 80% of files have no formulas or very few, again because they are really data files.
12854 (5.15%) have formulas.

Only 737 had VBA code, and 472 of them had unique VBA content as determined by a MD5 hash.
They have a range of typically 10 to 2000 lines of code.
102 have “Macro recorded by…” and no Dim statements
Only 78 of 472 have Option Explicit

I have prepared a slide deck of the findings, available at: (185K PDF)

Does this interest anyone?

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SoftTest Ireland Conference 2015 – Future Proof your Software Testing

SoftTest Ireland in association with the ISA Software Skillnet are hosting a one-day national conference for software test professionals.

Date: Wednesday 23rd September 2015 9am – 5.30pm
Venue: Clyde Court Hotel, Ballsbridge, Dublin 4

Cost: €100.00 per delegate
Book here:

Software testing is experiencing an industry disrupting revolution, driven by rapidly evolving technologies and software delivery paradigms.
Understand the critical technologies to be learned, key skills to be developed and the professional persona required by testers to further enhance their value into the future.

Explore the future of testing with expert speakers on topics such as;
The Internet of Things
Cloud Test Ops
Test Automation
Personal professional development

9 Speakers: Paul Gerrard, Chris Ambler, Colm Harrington, Declan O’Riordan, Claire Goss, Augusto Evangelisti, Stephen Janaway, Jonathan Wright, Matt Wynn—future-proof-your-software-testing/
t: @softtestireland

SoftTest Ireland

Interest group for software testers in Ireland

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VBA in the spreadsheets from the Enron email corpus

The European Spreadsheet Risk 2015 Conference papers are now available at

My presentation was on investigating the use of VBA in spreadsheets in the Enron email corpus.

Most of the slides deal with the mechanics of how I did it, and statistics on the 538 workbooks found with unique VBA content. The network graph I did for interest was #madewithgephi.

Workbook VBA code similarity

Workbook VBA code similarity

Some conclusions I came to are:

1) The workbooks are probably not typical of the routine mass of everyday spreadsheets.
If people email spreadsheets to others, I infer that they don’t have a shared folder on the network. Therefore these workbooks are for communication. So, they are probably not an insight into the real ‘dark matter’ of EUC that stays in shared folders and never emailed – eg routine accounting workbook.

2) Apart from simple static analysis which gives a general indicator of code quality, it is very difficult to say if the VBA contains errors.
The real test is in execution of the code. But we cannot reproduce the environment in which these workbooks were created. The files we have are probably circulated as reports for reading, so after the execution of the code. Therefore do not have the preconditions to run the code. Static analysis like TM-VBA inspector only goes so far.
Code inspection can raise questions of unsafe practices and assumptions, but is time consuming.

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XLTest 1.55 released

I have updated my spreadsheet auditing addin.
Changes in version 1.55
1.    On startup, it checks and fixes autonumber seed problems in database
2.    Processing limit of 1 million cells made an option
3.    ExportActiveProject procedure runnable by VBA automation
4.    VBA Sort Procedures option
5.    Option to list all sheet statistics separately when scanning files
6.    Demo / 30-day evaluation version made available
7.    Utility option to display current autofilter criteria
8.    Numerous usability tweaks

In order to make a time limited trial available I am now protecting it using the ‘Unviewable VBA’ app from Petros Chatzipantazis:

He also markets a Ribbon Commander addin intended to make Ribbon customisation easier than XML.

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