BUG: VB Crashes After Ending Application While in Break Mode

ID: Q183162


The information in this article applies to:
  • Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, version 5.0


SYMPTOMS

While debugging your application in Break mode, Visual Basic may terminate, hang, or cause one or both of the following errors when you end the application:

Run-time error '28': Out of stack space
-or-
VB5 caused a stack fault in module KERNEL32.DLL at 0137:bff725c5.

NOTE: The memory address at which the error occurs may vary.


CAUSE

This problem can occur when multiple forms are shown modally. The problem only occurs at design-time when you use the Immediate Window while in Break mode and then end the application.


RESOLUTION

One workaround for this problem is to avoid using the Immediate Window while your forms are shown modal or to show your forms modeless instead of modal. You can show a form modeless yet simulate most of the functionality of showing a form modal by setting the form's ShowInTaskbar property to False and by setting the Enabled property of the other visible forms to False, which prevents users from setting focus to the other forms. When the user dismisses the form, reset the Enabled property of the other visible forms as appropriate.


STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this bug and will post new information here in the Microsoft Knowledge Base as it becomes available.


MORE INFORMATION

Steps to Reproduce Behavior

  1. Create a new Standard EXE project. Form1 is created by default.


  2. Put a CommandButton on Form1.


  3. Add the following code to Form1:
    
          Private Sub Command1_Click()
             Dim frm as Form1
             Set frm = New Form1
             frm.Show vbModal 'problem does not occur when showing
                              'forms modeless: frm.Show vbModeless
          End Sub
     


  4. Run the project. Press enter 29 times to load 30 forms. (Each time you press Enter, the Command1_Click code shows a modal copy of Form1.)


  5. Press the CTRL+BREAK keys to enter Break mode.


  6. Press the CTRL+G keys to view the Immediate Window, and then type:

    ? "Hello"


  7. End the project by clicking the END button on the toolbar. Note Visual Basic hangs or terminates as described previously.


Additional query words: access violation illegal operation page fault ipf Gpf kbVBp500bug
kbVBp kbDSupport kbdsd

Keywords : kbGrpVB
Version : WINDOWS:5.0
Platform : WINDOWS
Issue type : kbbug


Last Reviewed: January 5, 2000
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