Microsoft KB Archive/174519

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The information in this article applies to:


 * ActiveX Data Objects (ADO), version 1.5
 * Microsoft Transaction Server 1.0

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SYMPTOMS
Preliminary and beta releases of ODBC 3.5 included a version of the connection pooling component (Mtxdm.dll) that disables Microsoft Transaction Server (MTS) 1.X. If you have this version of Mtxdm.dll, you may see one or all of the following symptoms:

 When starting the MTS Explorer, the startup graphic appears, and then nothing happens for two to three minutes. If the Explorer window appears (and it may not), you will not be able to access any of the MTS functions.  After attempting to use MTS, within the Windows NT Event Viewer, you will find the following Transaction Server Application log:

The run-time environment has detected the absence of a critical resource and has caused the process that hosted it to fail fast.

 You will also be unable to create MTS objects.

ODBC 3.5 now ships as a part of the Microsoft Data Access Components (MDAC) version 1.5. MDAC 1.5 includes ODBC 3.5, OLE-DB 1.5, ActiveX Data Objects (ADO) 1.5, and Remote Data Service (RDS) 1.5. If any MDAC 1.5 component is installed on a computer, it will require the presence of ODBC 3.5, and therefore, install the version of Mtxdm.dll that will disable MTS 1.X.

CAUSE
The calling convention used internally within Mtxdm.dll was changed for MTS 2.0 beta 2 / beta 3 and is incompatible with previous versions of MTS. When distributed with MTS 2.0 beta 2 /beta 3, no problem occurs. But when Mtxdm.dll is distributed to systems with MTS 1.X without upgrading to MTS 2.0, it will disable MTS 1.X.

Mtxdm.dll provides support for connection pooling and is an integral component of both Microsoft Transaction Server as well as ODBC. Any MTS 1.X system where ODBC 3.5 (or related MDAC components) has been installed without MTS 2.0 will encounter the symptoms described in the SYMPTOMS section.

RESOLUTION
The solution is to use version 1997.06.394.0 of Mtxdm.dll. This DLL is available either with the MDAC 1.5a components (available 10/6/97 from Microsoft's Web site), or to contact Product Support to obtain a copy.

MTS 1.X shipped with version 1997.03.14.222 of Mtxdm.dll; however, you will need the newer version to work correctly with MDAC 1.5/1.5a components.

Installing MDAC 1.5a, though, will not be sufficient to repair a disabled MTS 1.X system. Please contact Microsoft Technical Support for instructions.

MORE INFORMATION
The remaining text describes what versions of Mtxdm.dll, beta and release, contribute or resolve the symptoms described in the SYMPTOMS section.

The Version of Mtxdm.dll That Disables MTS 1.X
Several versions of Mtxdm.dll have shipped that can disable MTX 1.X. Versions 1997.06.395.0 through 1997.09.484.0 will create this problem. Mtxdm.dll in this version range has been released with the following products.


 * Internet Explorer 4.0 Client SDK
 * Internet Information Server 4.0 Beta 2 (including MTS 2.0 Beta 2)
 * Internet Information Server 4.0 Beta 3 (including MTS 2.0 Beta 3)
 * Microsoft Data Access Components Version 1.5.

The version of Mtxdm.dll That Will Not Disable MTS 1.X
Version 1997.06.394.0 of Mtxdm.dll uses the same calling convention as MTS 1.X, and ships with the following product:


 * Microsoft Data Access Components Version 1.5a (available 10/6/97)

Using version 1997.06.394.0 will allow both ODBC 3.5 and MTS 1.X to coexist on the same computer. However, because the version of Mtxdm.dll that ships with MDAC 1.5a is less than the version number for any customer using the MTS 2.0 beta, it will not replace the version required by MTS 2.0 beta. This should not be an issue, assuming that if you have MTS 2.0 on a given machine, you are not using MTS 1.X on that same machine.

Distributing MDAC 1.5a components to computers with MTS 1.X should not disable MTS 1.X.

Installing MDAC 1.5a will not be sufficient to repair a disabled MTS 1.X installation. Please contact Microsoft Technical Support for instructions.

The Final Version of Mtxdm.dll That Ships with MTS 2.0
With the release version of MTS 2.0, there will be a new version of Mtxdm.dll, which uses the original calling convention required by MTS 1.X, and which has a higher file version than anything that has yet shipped. This version of Mtxdm.dll will be shipping with the following products:


 * Internet Information Server 4.0 (available Q4 1997)
 * Microsoft Transaction Server 2.0 (available Q4 1997)