Open Software Solutions

Consider the following scenario:

•	You build a Microsoft .NET Framework 3.5-based application in debug mode. For example, in the Web.config file for a .NET Framework 3.5-based Web application, you set the debug option as follows: debug=true
•	You use Microsoft Visual Basic 2008 as the programming language.
•	The application depends on many assemblies and references.

In this scenario, the Visual Basic compiler (Vbc.exe) may use 100 percent of the CPU resources. Additionally, you may receive an error message that resembles the following:

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This issue may occur because the CPU computes lots of debug data when you build the application in debug mode. How much debug data is computed depends on the size of the project and on the number of references. In some cases, the debug data is computed multiple times.

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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 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.
Note After you install this hotfix, the CPU computes the debug data only one time. This change minimizes the workload for the compiler and resolves the issue that is mentioned in the Symptoms section. To completely resolve the problem, we recommend that you also install the Visual Basic 2008 hotfix that is provided in the following Microsoft Knowledge Base article:

Prerequisites

To apply this hotfix, you must have the .NET Framework 3.5 installed.

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 name	File version	File size	Date	Time	Platform
Vbc.exe	9.0.21022.113	1,710,584	03-Jun-2008	06:50	x86
Vbc.exe	9.0.21022.113	2,346,488	03-Jun-2008	07:02	x64
Vbc.exe	9.0.21022.113	4,620,280	03-Jun-2008	07:02	IA-64

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To work around this issue, use one of the following methods.

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Method 1

Build the application in release mode.

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Method 2

If you are trying to build a Web application, set the debug option as follows in the Web.config file:

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

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

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