FIX: You cannot browse an ASP.NET 1.1 Web site if the User-Agent string that is in the browser contains more than 256 characters

You visit a Microsoft ASP.NET 1.1 Web site by using a browser that has a User-Agent string that contains more than 256 characters. However, you cannot browse the site. Additionally, the layout of the site is incorrect.

This problem occurs because ASP.NET 1.1 does not recognize the browser when the User-Agent string contains more than 256 characters. When ASP.NET 1.1 does not recognize the browser,, the content on the Web site is not rendered correctly.

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: 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

You must have the Microsoft .NET Framework 1.1 Service Pack 1 (SP1) installed to apply this hotfix.

Restart requirement

You must restart the computer if any of the affected files are being used when you install this hotfix. You do not have to restart the computer if you close all ASP.NET Web sites before you install this hotfix.

Hotfix replacement information

This hotfix does not replace other hotfixes.

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 1.1 SP1

For all supported x86-based versions of Windows Server 2003 that have the .NET Framework 1.1 SP1 installed

Installation notes

Two hotfixes are provided for this problem. Download and apply the appropriate hotfix for the operating system that your computer is running.

• If your computer is running an x86-based version of Windows Server 2003, download and install the hotfix that is marked for "the .NET Framework 1.1 for Windows Server 2003."
• If your computer is running another operating system (this includes x64-based versions of Windows Server 2003 and IA64-based versions of Windows Server 2003), download and install the hotfix that is marked for "the .NET Framework 1.1 (MSI install)."

Note After you apply the hotfix, ASP.NET 1.1 can recognize User-Agent strings that contain as many as 512 characters.

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

When you visit a Web site, your browser sends the User-Agent string to the Web server that hosts the Web site. The Web server uses the User-Agent string to provide content that is customized for your browser.

To view the User-Agent string of your browser, type the following text into the address bar: To view the length of your browser’s User-Agent string, type the following text into the address bar:For more information about User-Agent strings, visit the following Microsoft Developer Network (MSDN) Web site: To resolve the same problem for ASP.NET 2.0 Web sites, download and apply the hotfix that is described in the following Microsoft Knowledge Base article: