An application that uses the Remote Desktop Connection ActiveX control to provide virtualized sessions crashes in Windows Server 2008 R2 or in Windows 7

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Article ID: 2446026 - View products that this article applies to.
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SYMPTOMS

Consider the following scenario:
  • You have a computer that is running Windows Server 2008 R2 or Windows 7.
  • You run an application that uses the Remote Desktop Connection ActiveX control (Mstscax.dll) to provide virtualized sessions.
  • Multiple user accounts are running applications in the virtualized sessions provided by the application.
In this scenario, the application crashes, and all virtualized sessions are disconnected.

Note This issue also occurs in Windows MultiPoint Server 2010. The SRCShell.exe in Windows MultiPoint Server 2010 uses Mstscax.dll to provide virtualized sessions. After this issue occurs, the SRCShell.exe crashes.

CAUSE

This issue occurs because an access violation exception occurs in the application that provides virtualized sessions when uninitialized variables are accessed. The uninitialized variables occur because the Desktop Windows Manager (DWM) is disabled on the remote desktop server when an application on the server opens a virtual channel to the DWM proxy on the client.

Note The Remote Desktop Protocol (RDP) enables virtual channels between a server and a client to transfer specific information. The clipboard, the remote audio, and the DWM all use this mechanism to relay information on the server to their proxies that are located on the client.

RESOLUTION

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft website:
http://support.microsoft.com/contactus/?ws=support
Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

To apply this hotfix, you must be running one of the following operating systems:
  • Windows 7
  • Windows 7 Service Pack 1 (SP1)
  • Windows Server 2008 R2
  • Windows Server 2008 R2 Service Pack 1 (SP1)

Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

Restart requirement

You do not have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The global version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.
Windows 7 and Windows Server 2008 R2 file information notes
Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.
  • The files that apply to a specific product, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.
    Collapse this tableExpand this table
    VersionProductSR_LevelService branch
    6.1.760 0.20xxxWindows 7 and Windows Server 2008 R2RTMLDR
    6.1.760 1.17xxxWindows 7 and Windows Server 2008 R2SP1GDR
    6.1.760 1.21xxxWindows 7 and Windows Server 2008 R2SP1LDR
  • GDR service branches contain only those fixes that are widely released to address widespread, very important issues. LDR service branches contain hotfixes in addition to widely released fixes.
  • The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2 and for Windows 7" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.
For all supported x86-based versions of Windows 7
Collapse this tableExpand this table
File nameFile versionFile sizeDateTimePlatform
Mstsc.exe6.1.7600.208611,034,75218-Dec-201005:25x86
Mstsc.mofNot applicable1,19922-Jul-200923:03Not applicable
Mstsc.exe6.1.7601.216241,049,60018-Dec-201007:56x86
Mstsc.mofNot applicable1,19912-Nov-201023:41Not applicable
Aaclient.dll6.1.7600.20861131,58418-Dec-201005:25x86
Aaclient.mofNot applicable1,26122-Jul-200922:58Not applicable
Mstscax.dll6.1.7600.208612,705,40818-Dec-201005:29x86
Mstscax.mofNot applicable2,05422-Jul-200923:02Not applicable
Tsgqec.dll6.1.7600.2086136,86418-Dec-201005:30x86
Aaclient.dll6.1.7601.17514131,58420-Nov-201012:18x86
Aaclient.mofNot applicable1,26110-Jun-200921:14Not applicable
Mstscax.dll6.1.7601.216243,215,87218-Dec-201007:57x86
Mstscax.mofNot applicable2,05410-Jun-200921:17Not applicable
Tsgqec.dll6.1.7601.1751436,86420-Nov-201012:21x86
For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2
Collapse this tableExpand this table
File nameFile versionFile sizeDateTimePlatform
Mstsc.exe6.1.7600.208611,098,75218-Dec-201006:04x64
Mstsc.mofNot applicable1,19922-Jul-200923:22Not applicable
Mstsc.exe6.1.7601.216241,116,67218-Dec-201008:50x64
Mstsc.mofNot applicable1,19912-Nov-201023:42Not applicable
Aaclient.dll6.1.7600.20861158,72018-Dec-201006:04x64
Aaclient.mofNot applicable1,26122-Jul-200923:18Not applicable
Mstscax.dll6.1.7600.208613,155,96818-Dec-201006:08x64
Mstscax.mofNot applicable2,05422-Jul-200923:20Not applicable
Tsgqec.dll6.1.7600.2086144,03218-Dec-201006:09x64
Aaclient.dll6.1.7601.17514158,72020-Nov-201013:25x64
Aaclient.mofNot applicable1,26110-Jun-200920:31Not applicable
Mstscax.dll6.1.7601.216243,715,58418-Dec-201008:51x64
Mstscax.mofNot applicable2,05410-Jun-200920:34Not applicable
Tsgqec.dll6.1.7601.1751444,03220-Nov-201013:27x64
Mstsc.exe6.1.7600.208611,034,75218-Dec-201005:25x86
Mstsc.mofNot applicable1,19922-Jul-200923:03Not applicable
Mstsc.exe6.1.7601.216241,049,60018-Dec-201007:56x86
Mstsc.mofNot applicable1,19912-Nov-201023:41Not applicable
Aaclient.dll6.1.7600.20861131,58418-Dec-201005:25x86
Aaclient.mofNot applicable1,26122-Jul-200922:58Not applicable
Mstscax.dll6.1.7600.208612,705,40818-Dec-201005:29x86
Mstscax.mofNot applicable2,05422-Jul-200923:02Not applicable
Tsgqec.dll6.1.7600.2086136,86418-Dec-201005:30x86
Aaclient.dll6.1.7601.17514131,58420-Nov-201012:18x86
Aaclient.mofNot applicable1,26110-Jun-200921:14Not applicable
Mstscax.dll6.1.7601.216243,215,87218-Dec-201007:57x86
Mstscax.mofNot applicable2,05410-Jun-200921:17Not applicable
Tsgqec.dll6.1.7601.1751436,86420-Nov-201012:21x86
For all supported IA-64-based versions of Windows Server 2008 R2
Collapse this tableExpand this table
File nameFile versionFile sizeDateTimePlatform
Mstsc.exe6.1.7600.208611,661,95218-Dec-201005:13IA-64
Mstsc.mofNot applicable1,19922-Jul-200923:47Not applicable
Mstsc.exe6.1.7601.216241,696,25618-Dec-201009:34IA-64
Mstsc.mofNot applicable1,19912-Nov-201023:42Not applicable
Aaclient.dll6.1.7600.20861339,96818-Dec-201005:13IA-64
Aaclient.mofNot applicable1,26122-Jul-200923:44Not applicable
Mstscax.dll6.1.7600.208616,091,77618-Dec-201005:17IA-64
Mstscax.mofNot applicable2,05422-Jul-200923:46Not applicable
Tsgqec.dll6.1.7600.2086197,79218-Dec-201005:19IA-64
Aaclient.dll6.1.7601.21624339,96818-Dec-201009:35IA-64
Aaclient.mofNot applicable1,26110-Jun-200920:36Not applicable
Mstscax.dll6.1.7601.216246,301,69618-Dec-201009:35IA-64
Mstscax.mofNot applicable2,05410-Jun-200920:38Not applicable
Tsgqec.dll6.1.7601.1751497,79220-Nov-201010:28IA-64
Mstsc.exe6.1.7600.208611,034,75218-Dec-201005:25x86
Mstsc.mofNot applicable1,19922-Jul-200923:03Not applicable
Mstsc.exe6.1.7601.216241,049,60018-Dec-201007:56x86
Mstsc.mofNot applicable1,19912-Nov-201023:41Not applicable
Aaclient.dll6.1.7600.20861131,58418-Dec-201005:25x86
Aaclient.mofNot applicable1,26122-Jul-200922:58Not applicable
Mstscax.dll6.1.7600.208612,705,40818-Dec-201005:29x86
Mstscax.mofNot applicable2,05422-Jul-200923:02Not applicable
Tsgqec.dll6.1.7600.2086136,86418-Dec-201005:30x86
Aaclient.dll6.1.7601.17514131,58420-Nov-201012:18x86
Aaclient.mofNot applicable1,26110-Jun-200921:14Not applicable
Mstscax.dll6.1.7601.216243,215,87218-Dec-201007:57x86
Mstscax.mofNot applicable2,05410-Jun-200921:17Not applicable
Tsgqec.dll6.1.7601.1751436,86420-Nov-201012:21x86

WORKAROUND

Workaround for Windows 7 and for Windows Server 2008 R2

To work around the issue, start the DWM service on the computer.

Note This method causes drawback on the processing power on the computer and requires more bandwidth.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

MORE INFORMATION

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates
For more information about Windows MultiPoint Server 2010, visit the following Microsoft webpage:
Introduction to Windows MultiPoint Server 2010
This issue may occur when an application runs in a Remote Desktop Services session by executing the following call.
WTSVirtualChannelOpenEx(
  WTS_CURRENT_SESSION, 
  "dwmprox",
  WTS_CHANNEL_OPTION_DYNAMIC);

Additional file information

Additional file information for Windows 7 and for Windows Server 2008 R2

Additional files for all supported x86-based versions of Windows 7
Collapse this tableExpand this table
File nameX86_38c1b79260f0810e24b5f0dbc9074645_31bf3856ad364e35_6.1.7600.20861_none_529f73a7f1cbc162.manifest
File versionNot applicable
File size1,093
Date (UTC)21-Dec-2010
Time (UTC)00:25
PlatformNot applicable
File nameX86_fed5f1aec1f9e351fd4d9d556bcce782_31bf3856ad364e35_6.1.7601.21624_none_f5202520aa984226.manifest
File versionNot applicable
File size1,093
Date (UTC)21-Dec-2010
Time (UTC)00:25
PlatformNot applicable
File nameX86_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7600.20861_none_4e4de6cb9b7c1c97.manifest
File versionNot applicable
File size20,880
Date (UTC)18-Dec-2010
Time (UTC)05:59
PlatformNot applicable
File nameX86_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7601.21624_none_5062845f987f64c4.manifest
File versionNot applicable
File size20,880
Date (UTC)18-Dec-2010
Time (UTC)08:33
PlatformNot applicable
File nameX86_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7600.20861_none_305fa0f3400cc316.manifest
File versionNot applicable
File size131,498
Date (UTC)18-Dec-2010
Time (UTC)06:00
PlatformNot applicable
File nameX86_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7601.21624_none_32743e873d100b43.manifest
File versionNot applicable
File size140,967
Date (UTC)21-Dec-2010
Time (UTC)00:27
PlatformNot applicable
Additional files for all supported x64-based versions of Windows 7 and of Windows Server 2008 R2
Collapse this tableExpand this table
File nameAmd64_4a02d8c886c9a5383f88affa3c268863_31bf3856ad364e35_6.1.7600.20861_none_e82ba6834b2a5de7.manifest
File versionNot applicable
File size1,838
Date (UTC)21-Dec-2010
Time (UTC)00:25
PlatformNot applicable
File nameAmd64_8564218264cec6a742a4572f59fd71ef_31bf3856ad364e35_6.1.7601.21624_none_6b19cd11806929dc.manifest
File versionNot applicable
File size1,838
Date (UTC)21-Dec-2010
Time (UTC)00:25
PlatformNot applicable
File nameAmd64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7600.20861_none_aa6c824f53d98dcd.manifest
File versionNot applicable
File size20,886
Date (UTC)18-Dec-2010
Time (UTC)06:54
PlatformNot applicable
File nameAmd64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7601.21624_none_ac811fe350dcd5fa.manifest
File versionNot applicable
File size20,886
Date (UTC)18-Dec-2010
Time (UTC)09:27
PlatformNot applicable
File nameAmd64_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7600.20861_none_8c7e3c76f86a344c.manifest
File versionNot applicable
File size131,504
Date (UTC)18-Dec-2010
Time (UTC)06:56
PlatformNot applicable
File nameAmd64_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7601.21624_none_8e92da0af56d7c79.manifest
File versionNot applicable
File size140,973
Date (UTC)21-Dec-2010
Time (UTC)00:29
PlatformNot applicable
File nameWow64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7600.20861_none_b4c12ca1883a4fc8.manifest
File versionNot applicable
File size13,023
Date (UTC)18-Dec-2010
Time (UTC)05:51
PlatformNot applicable
File nameWow64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7601.21624_none_b6d5ca35853d97f5.manifest
File versionNot applicable
File size13,023
Date (UTC)18-Dec-2010
Time (UTC)08:24
PlatformNot applicable
File nameX86_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7600.20861_none_305fa0f3400cc316.manifest
File versionNot applicable
File size131,498
Date (UTC)18-Dec-2010
Time (UTC)06:00
PlatformNot applicable
File nameX86_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7601.21624_none_32743e873d100b43.manifest
File versionNot applicable
File size140,967
Date (UTC)21-Dec-2010
Time (UTC)00:29
PlatformNot applicable
Additional files for all supported IA-64-based versions of Windows Server 2008 R2
Collapse this tableExpand this table
File nameIa64_50c1bac89f43ad634570a46a1689368a_31bf3856ad364e35_6.1.7601.21624_none_dc82a71e6603f95e.manifest
File versionNot applicable
File size1,835
Date (UTC)21-Dec-2010
Time (UTC)00:25
PlatformNot applicable
File nameIa64_cf1e802747784a5b4c58b71cb7ee9e02_31bf3856ad364e35_6.1.7600.20861_none_5286baa16736741a.manifest
File versionNot applicable
File size1,835
Date (UTC)21-Dec-2010
Time (UTC)00:25
PlatformNot applicable
File nameIa64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7600.20861_none_4e4f8ac19b7a2593.manifest
File versionNot applicable
File size20,883
Date (UTC)18-Dec-2010
Time (UTC)06:53
PlatformNot applicable
File nameIa64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7601.21624_none_50642855987d6dc0.manifest
File versionNot applicable
File size20,883
Date (UTC)18-Dec-2010
Time (UTC)09:59
PlatformNot applicable
File nameIa64_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7600.20861_none_306144e9400acc12.manifest
File versionNot applicable
File size131,501
Date (UTC)18-Dec-2010
Time (UTC)06:53
PlatformNot applicable
File nameIa64_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7601.21624_none_3275e27d3d0e143f.manifest
File versionNot applicable
File size140,970
Date (UTC)21-Dec-2010
Time (UTC)00:25
PlatformNot applicable
File nameWow64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7600.20861_none_b4c12ca1883a4fc8.manifest
File versionNot applicable
File size13,023
Date (UTC)18-Dec-2010
Time (UTC)05:51
PlatformNot applicable
File nameWow64_microsoft-windows-t..minalservicesclient_31bf3856ad364e35_6.1.7601.21624_none_b6d5ca35853d97f5.manifest
File versionNot applicable
File size13,023
Date (UTC)18-Dec-2010
Time (UTC)08:24
PlatformNot applicable
File nameX86_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7600.20861_none_305fa0f3400cc316.manifest
File versionNot applicable
File size131,498
Date (UTC)18-Dec-2010
Time (UTC)06:00
PlatformNot applicable
File nameX86_microsoft-windows-t..s-clientactivexcore_31bf3856ad364e35_6.1.7601.21624_none_32743e873d100b43.manifest
File versionNot applicable
File size140,967
Date (UTC)21-Dec-2010
Time (UTC)00:25
PlatformNot applicable

Properties

Article ID: 2446026 - Last Review: February 10, 2011 - Revision: 1.0
APPLIES TO
  • Windows Server 2008 R2 Datacenter
  • Windows Server 2008 R2 Enterprise
  • Windows Server 2008 R2 for Itanium-Based Systems
  • Windows Server 2008 R2 Foundation
  • Windows Server 2008 R2 Standard
  • Windows Multipoint Server 2010
  • Windows Multipoint Server 2010 Academic
  • Windows 7 Enterprise
  • Windows 7 Professional
  • Windows 7 Ultimate
Keywords: 
kbautohotfix kbqfe kbhotfixserver kbfix kbsurveynew kbexpertiseinter KB2446026

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