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A hotfix is available for the ASP.NET browser definition files in the Microsoft .NET Framework 4.0

Article ID: 2600088 - View products that this article applies to.

SUMMARY

This article describes a hotfix for the ASP.NET browser definition files that are included in the Microsoft .NET Framework 4.0.

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This hotfix introduces updated definitions in the browser definition files for Internet Explorer and for Mozilla Firefox. The browser definition files are stored in one of the following folders, depending on the installed version of the Microsoft .NET Framework:

For 32-bit versions of the .NET Framework 4.0

%WinDir%\Microsoft.NET\Framework\v4.0.30319\CONFIG\Browsers
For 64-bit versions of the .NET Framework 4.0

%WinDir%\Microsoft.NET\Framework64\v4.0.30319\CONFIG\Browsers

By default, ASP.NET uses sniffing technology for the user agent string to detect browsers. The browser definition files cover a certain range of browser versions. However, as the version numbers increase, ASP.NET might not recognize new versions of a browser by using the user agent string. In this case, ASP.NET might handle these versions as an unknown browser. For example, ASP.NET cannot recognize Windows Internet Explorer 10 that has the following user agent string:

Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/6.0)

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that 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

(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 have the .NET Framework 4 installed.

Restart information

After you apply this hotfix, you might have to restart the computer if any affected files are being used when you install this hotfix.

To avoid a restart of the computer, shut down all web server applications for ASP.NET websites before you apply this hotfix.

Replacement information

This hotfix does not replace a previously-released hotfix.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

For all supported x86-based versions of the .NET Framework 4.0

Collapse this tableExpand this table

File name	File version	File size	Date	Time	Platform
Aspnet_wp.exe	4.0.30319.504	32,592	22-Aug- 2011	06:03	x86
Firefox.browser	Not applicable	3,082	21-Aug-2011	22:10	Not applicable
Ie.browser	Not applicable	4,283	21-Aug-2011	22:10	Not applicable
Setup.dll	10.0.30319.504	295,760	22-Aug- 2011	06:03	x86
Setupengine.dll	10.0.30319.504	809,304	22-Aug- 2011	06:03	x86
Setupui.exe	10.0.30319.504	78,152	22-Aug- 2011	06:03	x86
System.web.dll	4.0.30319.504	5,227,856	22-Aug- 2011	06:03	x86
System.web.extensions.dll	4.0.30319.504	1,862,504	22-Aug- 2011	06:03	x86
Webengine.dll	4.0.30319.504	14,160	22-Aug- 2011	06:03	x86
Webengine4.dll	4.0.30319.504	495,440	22-Aug-2011	06:03	x86

For all supported x64-based versions of the .NET Framework 4.0

Collapse this tableExpand this table

File name	File version	File size	Date	Time	Platform
Aspnet_wp.exe	4.0.30319.504	40,784	22-Aug- 2011	06:38	x64
Firefox.browser	Not applicable	3,082	21-Aug-2011	21:37	Not applicable
Ie.browser	Not applicable	4,283	21-Aug-2011	21:37	Not applicable
Setup.dll	10.0.30319.504	295,760	22-Aug- 2011	06:03	x86
Setupengine.dll	10.0.30319.504	809,304	22-Aug- 2011	06:03	x86
Setupui.exe	10.0.30319.504	78,152	22-Aug- 2011	06:03	x86
System.web.dll	4.0.30319.504	5,197,136	22-Aug- 2011	06:38	x64
System.web.extensions.dll	4.0.30319.504	1,862,504	22-Aug- 2011	06:03	x86
Webengine.dll	4.0.30319.504	15,696	22-Aug- 2011	06:38	x64
Webengine4.dll	4.0.30319.504	720,720	22-Aug-2011	06:38	x64

For all supported IA-64–based versions of the .NET Framework 4.0

Collapse this tableExpand this table

File name	File version	File size	Date	Time	Platform
Aspnet_wp.exe	4.0.30319.504	80,208	22-Aug- 2011	07:09	IA-64
Firefox.browser	Not applicable	3,082	21-Aug-2011	22:12	Not applicable
Ie.browser	Not applicable	4,283	21-Aug-2011	22:12	Not applicable
Setup.dll	10.0.30319.504	295,760	22-Aug- 2011	06:03	x86
Setupengine.dll	10.0.30319.504	809,304	22-Aug- 2011	06:03	x86
Setupui.exe	10.0.30319.504	78,152	22-Aug- 2011	06:03	x86
System.web.dll	4.0.30319.504	4,816,208	22-Aug-2011	07:09	IA- 64
System.web.extensions.dll	4.0.30319.504	1,862,504	22-Aug- 2011	06:03	x86
Webengine.dll	4.0.30319.504	25,424	22-Aug-2011	07:09	IA- 64
Webengine4.dll	4.0.30319.504	1,340,752	22-Aug-2011	07:09	IA-64

Note Because of file dependencies, this hotfix might also contain other files.

Common issues that occur without this hotfix

Issue 1

Consider the following scenario:

You use Windows Internet Explorer 10 to access an ASP.NET-based webpage.
The webpage starts a postback.

In this scenario, the postback fails, and you receive the following error message:

Script Error encountered", "'__doPostBack' is undefined

Note The webpage can start a postback in various ways. For example, a LinkButton control can start a postback.

Issue 2

Consider the following scenario:

You create an ASP.NET-based webpage that has the MaintainScrollPositionOnPostBack attribute set to True.
You use Mozilla Firefox 4.0 or a later version of Mozilla Firefox to open the webpage.
The webpage starts a postback.

In this scenario, the scroll position of the webpage is not maintained after postback.

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REFERENCES

For more information about the MaintainScrollPositionOnPostBack attribute, visit the following Microsoft website:

General information about the MaintainScrollPositionOnPostBack attribute

(http://msdn.microsoft.com/en-us/library/950xf363.aspx)

For more information about the browser definition file schema, visit the following Microsoft website:

General information about the browser definition file schema

(http://msdn.microsoft.com/en-us/library/ms228122(v=VS.100).aspx)

For more information about the Internet Explorer 10 user agent string, visit the following Microsoft website:

General information about the Internet Explorer 10 user agent string

(http://blogs.msdn.com/b/ie/archive/2011/04/15/the-ie10-user-agent-string.aspx)

For more information about how to detect Internet Explorer more effectively, visit the following Microsoft website:

How to detect Internet Explorer more effectively

(http://msdn.microsoft.com/en-us/library/ms537509(v=VS.85).aspx)

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.

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