Q193502: PRB: Cannot Quit VFP End Task Causes Application Error

Article: Q193502
Product(s): Microsoft FoxPro
Version(s): WINDOWS:3.0,3.0b,5.0,5.0a
Operating System(s): 
Keyword(s): kbvfp kbvfp500 kbvfp500a kbvfp500aBUG kbvfp600 kbvfp600fix kbXBase
Last Modified: 08-DEC-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0, 5.0a, on platform(s):
   - the operating system: Microsoft Windows NT 
   - the operating system: Microsoft Windows 95 
   - the operating system: Microsoft Windows 98 
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SYMPTOMS
========

Running a Visual FoxPro form through a READ EVENTS command without a CLEAR
EVENTS command, produces an error dialog box, which contains an OK button. The
following text displays in the error dialog box:

  Cannot Quit Visual FoxPro

If the OK button is not selected and the error dialog box remains on the Visual
FoxPro screen, when End Task is selected from the Task Manager, one of the
following system errors appear (depending on the version of the operating
system):

- In Windows 95, and in Windows 98, using Visual FoxPro 5.0x, the following
  error displays:

  This program has performed an illegal operation and will be shut down.

  Clicking the Details button reveals the following message:

  VFP caused an invalid page fault in module <unknown> at <memory
  address>.

- In Windows 95 and in Windows 98, using Visual FoxPro 6.0, the following error
  appears:

  This program has performed an illegal operation and will be shut down.

  Clicking the Details button reveals the following message:

  VFP caused an invalid page fault in module KERNEL32.DLL at <memory
  address>.

- In Windows NT 4.0, using Visual FoxPro 5.0x, the following error appears:

  An application error has occurred and an application error log is being
  generated.

  VFP.exe
  Exception: access violation <error number>, Address: <memory
  address>.

- In Windows NT 4.0, using Visual FoxPro 6.0, the problem does not occur.

CAUSE
=====

Not clearing the "Cannot Quit Visual FoxPro" error dialog box by selecting the
OK button prior to selecting End Task from the Task Manager.

RESOLUTION
==========

Clear the "Cannot Quit Visual FoxPro" error dialog box by selecting the OK
button prior to using End Task and the error does not occur.

STATUS
======

Microsoft is researching this problem and will post new information here in the
Microsoft Knowledge Base as it becomes available.

MORE INFORMATION
================

Steps to Reproduce Behavior
---------------------------

WARNING: The following steps cause Visual FoxPro to crash and you may not be able
to restart Visual FoxPro unless you turn your computer off and on (perform a
cold boot).

NOTE: The following example would not normally be performed by a programmer using
Visual FoxPro, however it is used here because it is the easiest way to
demonstrate the problem.

1. Create a program with the following FoxPro command:

  

  READ EVENTS

2. Save and run the program.

3. Try to quit Visual FoxPro, by closing the Visual FoxPro window.

4. The following error displays in a dialog box, which contains an OK button:

  Cannot Quit Visual FoxPro.

5. Do NOT select the OK button and keep the error dialog box on the screen.

6. Invoke the Windows Task Manager and select the End Task button.

  NOTE: You may need to select End Task more than once.

7. One of the error messages listed in the SYMPTOMS section occurs.

REFERENCES
==========

For more information, please see the following article in the Microsoft
Knowledge Base:

  Q172455 SAMPLE: Exitfox.exe Overcomes "Cannot Quit Visual FoxPro" Error

(c) Microsoft Corporation 1998. All Rights Reserved. Contributions by Perry
Newton, Microsoft Corporation.


Additional query words: exit close quit

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Keywords          : kbvfp kbvfp500 kbvfp500a kbvfp500aBUG kbvfp600 kbvfp600fix kbXBase 
Technology        : kbVFPsearch kbAudDeveloper
Version           : WINDOWS:3.0,3.0b,5.0,5.0a
Issue type        : kbprb

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