Eror message on a client computer that is running Windows Vista or Windows Server 2008: "ERROR_NOT_LOCKED (158)"

Consider the following scenario in a network environment:

• You set up a file share on a server that is running Windows Vista or Windows Server 2008.
• You have a client computer (client 1) that is running Windows Vista or Windows Server 2008.
• You also have another client computer (client 2) that is running a Windows operating system that is earlier than Windows Vista. For example, you have a client computer that is running Windows XP or Windows Server 2003.
• You run two applications on client 1. At the same time, you run one application on client 2. All the three applications perform file I/O operations to the file share. For example, these applications may lock part of a file on the file share, edit and then unlock the file.

In this scenario, one of the applications on client 1 fails, and all the other applications stop working.

To monitor the file I/O activity of the three applications, you can use Process Monitor. When you experience this issue, you will find that an error that resembles the following is logged for the affected application: Process Monitor also indicates that the error occurs in the UnlockFile function.

This issue occurs because of a race condition between two versions of the Server Message Block (SMB) environment. Windows operating systems that are earlier than Windows Vista use SMB1. However, Windows Vista and Windows Server 2008 use SMB2. In a mixed SMB1 and SMB2 environment, when several applications are performing file I/O operations to a file share, the applications may form a "lock-lock-unlock" cycle. In this situation, an "ERROR_NOT_LOCKED" error occurs.

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 Web site: 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, your computer must be running Windows Vista Service Pack 2 or Windows Server 2008 Service Pack 2.

For more information about how to obtain a Windows Vista service pack, click the following article number to view the article in the Microsoft Knowledge Base: For more information about how to obtain a Windows Server 2008 service pack, click the following article number to view the article in the Microsoft Knowledge Base:

Registry information

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

Restart requirement

You must 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 Vista and Windows Server 2008 file information notes

Important Windows Vista hotfixes and Windows Server 2008 hotfixes are included in the same packages. However, only "Windows Vista" is listed on the Hotfix Request page. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows Vista" 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.

  Version	Product	SR_Level	Service branch
  6.0.600 2 . 22xxx	Windows Vista and Windows Server 2008	SP2	LDR

• 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 and for Windows Vista" section. MUM files and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintaining the state of the updated component. 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 Server 2008 and of Windows Vista

For all supported x64-based versions of Windows Server 2008 and of Windows Vista

For all supported IA-64-based versions of Windows Server 2008

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

For more information about the UnlockFile function, visit the following Microsoft Web site: For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

Additional file information

Additional file information for Windows Vista and for Windows Server 2008

Additional files for all supported x86-based versions of Windows Vista and of Windows Server 2008

Additional files for all supported x64-based versions of Windows Vista and of Windows Server 2008

Additional files for all supported IA-64-based versions of Windows Server 2008