"COMException" error from WPF applications after the .NET Framework 4.7 is installed on Windows 7 or Windows Server 2008 R2

Consider the following scenario:

• You have a touch device that is running Windows 7 Service Pack 1 (SP1) or Windows Server 2008 R2 SP1.
• Some Windows Presentation Framework (WPF) applications are running on the device.
• You install the May 2017 Preview of Quality Rollup for the .NET Framework 4.6, 4.6.1, and 4.6.2 (KB 4104606) on the device.
• You then install the .NET Framework 4.7 on the device.

In this scenario, the WPF applications fail and generate error messages that resemble the following message:

To resolve this problem, install the July 25, 2017, update for the .NET Framework 4.6, 4.6.1, 4.6.2, and 4.7 from the Microsoft Update Catalog.

Windows 7 SP1 and Windows Server 2008 R2 SP1

Download the stand-alone package from the Microsoft Update catalog. For more information about this update, see KB 4035510.

Windows 8.1 and Windows Server 2012 R2

Download the stand-alone package from the Microsoft Update catalog. For more information about this update, see KB 4035509.

Windows Server 2012

Download the stand-alone package from the Microsoft Update catalog. For more information about this update, see KB 4035508.

To work around this problem, uninstall and then reinstall the .NET Framework 4.7. Alternatively, temporarily disable the affected WPF touch component.

Uninstall the .NET Framework 4.7

1. In Control Panel, click Uninstall a program in the Programs category.
2. In the list of programs, locate and click Microsoft .NET Framework 4.7, and then click Uninstall/Change.
3. In the .NET Framework 4.7 Maintenance wizard, click Remove.NET Framework 4.7 from this computer, and then click Next.
4. If the following warning window appears, click Continue.
   
   
   
5. Wait for the uninstallation to complete.

Reinstall the .NET Framework 4.7

To reinstall the Microsoft .NET Framework 4.7, use one of the following methods.

Method 1: Manually download and install the .NET Framework 4.7

1. Download the web installer for the .NET Framework 4.7.
2. Install the .NET Framework 4.7.

Method 2: Use Windows Update to install the .NET Framework 4.7

1. Open Windows Update.
2. Click Check online for updates from Windows Update.
3. After the search for updates is complete, click Optional Updates available.
   
   
   
4. Locate and select Microsoft .NET Framework for Windows 7 and Windows Server 2008 R2, and then click OK.
   
   
   
5. Wait for the installation to complete.

Temporarily disable touch and stylus support for your WPF applications

To temporarily disable touch and stylus support, use one of the following methods.

Note See the "Status" section of this article for information about a permanent solution.

• Add the following entry to the application configuration to disable touch and stylus support for WPF applications.

<runtime>

<AppContextSwitchOverrides value=" Switch.System.Windows.Input.Stylus.DisableStylusAndTouchSupport=true"/>

</runtime>

• Apply the following registry subkey to disable touch and stylus support for WPF applications machine-global.

  Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

  
  Registry location: HKEY_LOCAL_MACHINE\Software\[Wow6432Node\]Microsoft\.NETFramework\AppContext\Switch.System.Windows.Input.Stylus.DisableStylusAndTouchSupport
   

  Type: String
  Value: "true"

For more information about known issues in the .NET Framework 4.7, see Known issues for .NET Framework 4.7.