The SnmpMgrOpen function fails and returns a null session, and the GetLastError function returns a 0 in Windows Server 2003

When you run a Simple Network Management Protocol (SNMP) management program on a Microsoft Windows Server 2003-based computer, the SNMP service does not return accurate information. When this problem occurs, the SnmpMgrOpen function fails and returns a null session. Additionally, the GetLastError function returns a 0 instead of a correct error code.

Therefore, the SNMP management program cannot detect functional failure, and related functions fail unexpectedly.

This problem occurs if the following conditions are true:

• The SNMP management program is a multithread program.
• One thread calls the SnmpMgrOpen function and the SnmpMgrClose function in a loop.
• At the same time, another thread calls the SnmpMgrTrapListen function in a loop.

Note The problem does not occur when the same program runs in Windows Vista.

This problem occurs because of a synchronization issue in the Mgmtapi.dll module.

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 this specific problem. 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, you must have Windows Server 2003 Service Pack 1 installed on the computer. You cannot apply this hotfix on computers that are running Windows Server 2003 Service Pack 2.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any 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.

Windows Server 2003 with Service Pack 1, x86-based versions

Windows Server 2003 with Service Pack 1, Itanium-based versions

Windows Server 2003 with Service Pack 1, x64-based versions

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

For more information about a similar problem that occurs in Windows Server 2003, click the following article number to view the article in the Microsoft Knowledge Base: For more information about the SnmpMgrOpen function, visit the following Microsoft Developer Network Web site: For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: