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Q214755: BUG: VB 6 DLL Settings Cause Access Error During Shutdown

Article: Q214755
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:6.0,6.0 SP2
Operating System(s): 
Keyword(s): kbInternet kbMTS200 kbVBp600bug kbVS600bug kbVS600sp2bug kbVS600sp3fix kbWinDNA kbIISkb
Last Modified: 18-JUN-2001

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The information in this article applies to:

- Microsoft Visual Basic Professional Edition for Windows, version 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, version 6.0 
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SYMPTOMS
========

Using the Unattended Execution, Retain in Memory, and Single Threaded Threading
Model options with a Visual Basic DLL installed in Microsoft Transaction Server
(MTS) causes an access violation when the MTS package times out.

NOTE: The Access Violation can occur when a Visual Basic DLL is used with these
settings in any multithreaded environment, such as MTS, IIS, Internet Explorer
and so on.

RESOLUTION
==========

Ensure that Visual Studio 6, Service Pack 3 is installed.

Settings other than those specified in the SYMPTOMS section do not cause this
error. Specifically, the Apartment Threaded Threading Model option, which is
recommended for use with MTS, is safe to use.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

This bug was corrected in Visual Studio 6, Service Pack 3.

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

To reproduce this problem, do the following:

1. Create a Visual Basic 6 DLL with the Unattended Execution, Single Threaded,
  and Retain In Memory project properties set.

2. Install the DLL in a Microsoft Transaction Server package.

3. Run a client application that uses the DLL. This causes the package to start
  up.

4. Close the client application.

5. The access violation occurs when the package times out.

REFERENCES
==========

For additional information on using components built in Visual Basic in
multithreaded environments, click the article number below to view the article
in the Microsoft Knowledge Base:

  Q186273 BUG: AV Running VB-Built Component in Multi-Threaded Environment


Additional query words: multithread multi-thread

======================================================================
Keywords          : kbInternet kbMTS200 kbVBp600bug kbVS600bug kbVS600sp2bug kbVS600sp3fix kbWinDNA kbIIS kbbuglist
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVB600
Version           : WINDOWS:6.0,6.0 SP2
Issue type        : kbbug
Solution Type     : kbfix

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