When you install an update to the Microsoft .NET Framework, the installation process may fail and roll back. After the rollback is complete, some Microsoft .NET Framework files in the global assembly cache (GAC) are deleted. Therefore, some Microsoft .NET Framework applications may not run or may run incorrectly.

In the Microsoft Installer (MSI) log for the update installation, you may receive an error message that resembles the following:

This problem occurs because of the interaction of a bug in the Microsoft .NET Framework and some third-party applications. These applications put a lock on an assembly in the GAC and on the folder that contains the assembly at the same time. This problem has only been seen when you run a third-party application that uses third-party application virtualization technology to virtualize the Microsoft .NET Framework. 

Note Running a standard Microsoft .NET Framework application does not lock files or folders that are in the GAC in a manner that causes this problem.

If this problem has already occurred, you have to fix the Microsoft .NET Framework. For more information, see the “More information” section of this article.

If this problem has not occurred yet, you can install the hotfix package to prevent this problem during the installation of future updates.

Important This hotfix resolves the issue of assemblies being deleted from the GAC when an update installation fails and rolls back. It does not resolve update installation failures or the causes of a rollback.

Note This issue also occurs when you install an update to the Microsoft .NET Framework 1.1 Service Pack 1 (SP1). However, there is currently no hotfix for this situation.

Hotfix information

A supported hotfix is now available from Microsoft. However, it is intended to correct only the problem that is described in this article. Apply it only to systems that are experiencing this specific problem. This hotfix may 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.

To resolve this problem immediately, contact Microsoft Customer Support Services to obtain the hotfix. For a complete list of Microsoft Customer Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

General information about the hotfix files for each operating system and platform

Prerequisites

To apply this hotfix, you must have one of the following versions of the Microsoft .NET Framework installed on the computer.

• Microsoft .NET Framework 2.0 Service Pack 2 (SP2)
• Microsoft .NET Framework 3.5 Service Pack 1 (SP1)
• Microsoft .NET Framework 4.0

Restart requirement

You may have to restart the computer after you apply the hotfix.

Hotfix replacement information

This hotfix does not replace any other 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 the Microsoft .NET Framework 2.0 SP2 on all supported x86-based versions of Windows 2000, of Windows Server 2003, and of Windows XPFor the Microsoft .NET Framework 2.0 SP2 on all supported x64-based versions of Windows 2000, of Windows Server 2003, and of Windows XP

For the Microsoft .NET Framework 2.0 SP2 on all supported IA-64-based versions of Windows Server 2003

For the Microsoft .NET Framework 3.5 SP1 on all supported x86-based versions of Windows Vista SP2 and of Windows Server 2008 SP2For the Microsoft .NET Framework 3.5 SP1 on all supported x64-based versions of Windows Vista SP2 and of Windows Server 2008 SP2

For the Microsoft .NET Framework 3.5 SP1 on all supported IA-64-based versions of Windows Server 2008 SP2

For the Microsoft .NET Framework 4.0 on all supported x86-based versions of Windows XP, of Windows Server 2003, of Windows Vista, of Windows Server 2008, of Windows 7, and of Windows Server 2008 R2For the Microsoft .NET Framework 4.0 on all supported x64-based versions of Windows XP, of Windows Server 2003, of Windows Vista, of Windows Server 2008, of Windows 7, and of Windows Server 2008 R2For the Microsoft .NET Framework 4.0 on all supported IA-64-based versions of Windows Server 2003, of Windows Server 2008 and of Windows Server 2008 R2

To work around this problem, close all applications that use the Microsoft .NET Framework or that hold locks on files or folders in the GAC before you install any updates to the Microsoft .NET Framework. 

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

If this problem has already occurred on your computer, and if assemblies were removed from the GAC, you have to fix the Microsoft .NET Framework.

For more information about how to fix the Microsoft .NET Framework, click the following article number to view the article in the Microsoft Knowledge Base:

You may also consider using Aaron Stebner’s .NET Framework Cleanup Tool. For more information about the .NET Framework Cleanup Tool, visit the following Microsoft website:


For more information about Microsoft software updates, click the following article number to view the article in the Microsoft Knowledge Base:

For more information about the GAC, visit the following Microsoft website:

For more information about the Support policy for Microsoft programs that are running in a third-party application or software redirection program or in a third-party application or software virtualization environment, click the following article number to view the article in the Microsoft Knowledge Base: