In Microsoft Visual Studio 2010 Service Pack 1 (SP1), you create a Visual Studio Add-in project that targets the Microsoft .NET Framework 2.0.
You set a breakpoint in the project.
You start debugging the project.
In this scenario, the breakpoint that you set is not hit.
Note This problem does not occur when you use the release version of Microsoft Visual Studio 2010.
This problem occurs because Visual Studio treats the add-in as a .NET Framework 2.0-based application. However, the Devenv.exe configuration files force the application to load as a .NET Framework 4.0-based application. Therefore, Visual Studio debugs the application in the wrong runtime, and this causes the breakpoints not to be hit.
Important This hotfix is specifically for Visual Studio add-in projects. We do not recommend that you install this hotfix if you use Visual Studio to create Office add-in projects.
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 website:
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.
To apply this hotfix, you must have Microsoft Visual Studio 2010 Service Pack 1 (SP1) installed.
You do not have to restart the computer after you apply this hotfix. We recommend that you exit any instances of Visual Studio, its applications, or any .NET Framework applications before you apply this hotfix. Otherwise, you must restart Visual Studio.
Hotfix replacement information
This hotfix does not replace a previously released hotfix.
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.
Microsoft Visual Studio 2010 Service Pack 1
To work around this problem, use one of the following methods:
Target the Visual Studio Add-in project to the Microsoft .NET Framework 4.0 instead of to the Microsoft .NET Framework 2.0.
After you create the Visual Studio Add-in project, save the project, and restart Visual Studio to start debugging.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about how to use breakpoints to debug a project, visit the following Microsoft Developer Network (MSDN) website: