DOCUMENT:Q214755 18-JUN-2001 [vbwin] TITLE :BUG: VB 6 DLL Settings Cause Access Error During Shutdown PRODUCT :Microsoft Visual Basic for Windows PROD/VER:WINDOWS:6.0,6.0 SP2 OPER/SYS: KEYWORDS:kbInternet kbMTS200 kbVBp600bug kbVS600bug kbVS600sp2bug kbVS600sp3fix kbWinDNA kbIISkb ====================================================================== ------------------------------------------------------------------------------- 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 ------------------------------------------------------------------------------- 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 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.