FIX: You receive error MSB4018 when you run MSBuild.exe at a Visual Studio 2008 SP1 command prompt to build a large solution

When you run the MSBuild.exe tool at a Visual Studio 2008 Service Pack 1 (SP1) command prompt to build a large solution, you receive error messages that resemble the following:
error MSB4018: The "<task name>" task failed unexpectedly.
error MSB4018: System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown.
The problem occurs when your solution has one or more of the following characteristics:
  • The solution has a deep hierarchy of project references.
  • The solution includes many projects.
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 service pack 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.


You must have .NET Framework 3.5 with Service Pack 1 installed to apply this hotfix.

Restart requirement

You do not have to 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.
File nameFile versionFile sizeDateTimePlatform .dll3.5.30729.4100802,81621-Apr- 200916:22x86
File nameFile versionFile sizeDateTimePlatform 30729.4100729,08821-Apr-200916:30x64
If the problem still exists after you install the hotfix, follow these steps:
  1. In the Program Files\MSBuild\v3.5 folder, create a file named "Custom.After.Microsoft.Common.targets" that has the following content:
    <Project xmlns="">    <PropertyGroup>    </PropertyGroup>    <Target Name="AfterClean">            <CallTarget Targets="GetTargetPath" UseResultsCache="true" Condition="'$(UnloadProjectsOnCompletion)'=='true'"/>    </Target>    <Target Name="AfterBuild">            <CallTarget Targets="GetTargetPath" UseResultsCache="true" Condition="'$(UnloadProjectsOnCompletion)'=='true'"/>    </Target>     <Target Name="AfterPublish">            <CallTarget Targets="GetTargetPath" UseResultsCache="true" Condition="'$(UnloadProjectsOnCompletion)'=='true'"/>    </Target></Project>
  2. At the command prompt, go to the folder in which the Tfsbuild.proj file is located, and then run the following command:
    MSBuild.exe /tv:3.5 /p:UnloadProjectsOnCompletion=true /m /t:desktoprebuild tfsbuild.proj
    Note If you are not using Team Build to start Msbuild.exe, replace "tfsbuild.proj" with the name of your project file and replace "/t:desktoprebuild" with the target that you want to build.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

Article ID: 959162 - Last Review: 05/19/2009 16:45:26 - Revision: 1.0

Microsoft .NET Framework 3.5 Service Pack 1

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