FIX: VB 6 DLL Settings Cause Access Violation During MTS Shutdown

• Microsoft Visual Basic Professional and Enterprise Editions for Windows, version 6.0
• Microsoft Visual Studio versions 6.0, 6.0 SP2

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
Version : WINDOWS:6.0,6.0 SP2
Platform : WINDOWS
Issue type : kbbug