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FIX: Msadco.dll Update to Address Access Violation in Devenv.exe

View products that this article applies to.

This article was previously published under Q200244

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Random crashing may occur with Visual InterDev 6.0 and MDAC 2.0 when you edit Active Server Pages (ASP) or HTML pages that have HTML <OBJECT> references to Remote Data Service (RDS) DataControl objects (CLSID:BD96C556-65A3-11D0-983A-00C04FC29E33). Here is a sample error message:
DEVENV.EXE Exception: access violation (0xc0000005), Address: <address>

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This problem occurs because the development shell is performing some design-time calls to ADO/RDS when it encounters the DataControl object. ADO/RDS attempts to access an asynchronous thread that has been shut down by ADO/RDS.

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To resolve this problem, install MDAC version 2.1 or later. For information on obtaining the latest version of MDAC, see the following Microsoft Web site: To work around this problem, see the following article in the Microsoft Knowledge Base:
200683� BUG: Visual InterDev 6.0 or Visual J++ 6.0 Crash When You Edit HTML with RDS Objects
The QFE is a .zip file that contains the updated Msadco.dll.

This hotfix is engineered to work with MDAC build 2.0 SP1 and should only be applied to this specific build. To verify the build of MDAC, check the internal version number of Mdado15.dll, which should be 2.0.3002.23.


  1. Locate the Msadco.dll file on the target system.
  2. Check the version number, which should be 2.0.3002.23.
  3. Copy the new Msadco.dll file so that it replaces the existing one.
  4. At a command prompt, type regsvr32 msacdo.dll to register the DLL.
MDAC 2.1 fixes this problem. This QFE should not be applied to older MDAC versions or MDAC 2.1.

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Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

This bug was corrected in Visual Studio 6.0 Service Pack 3, which installs MDAC 2.1. For additional information about Visual Studio service packs, click the following article numbers to view the articles in the Microsoft Knowledge Base:
194022� INFO: Visual Studio 6.0 Service Packs, What, Where, Why

194295� HOWTO: Tell That a Visual Studio Service Pack Is Installed
To download the latest Visual Studio service pack, visit the following Microsoft Web site:

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Keywords: kbado210fix, kbbug, kberrmsg, kbfix, kbqfe, kbvs600sp3fix, KB200244

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Article Info
Article ID : 200244
Revision : 6
Created on : 8/7/2007
Published on : 8/7/2007
Exists online : False
Views : 403