Unable to read the project file 'client.csproj'. Could not load file or assembly 'Microsoft.Build.En

错误具体信息：

Unable to read the project file 'client.csproj'. Could not load file or assembly 'Microsoft.Build.Engine, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. 系统找不到指定的文件。

今天打开之前一个vs2005的项目，报出上面的错误，这个啥啊。昨天还是好好的，能够正常的打开的啊

于是，百度了一下：

搜到了这边文章：http://blog.sina.com.cn/s/blog_4696f46b01009mgd.html

里面提到：

RE:
Based on my experience, probably the NET Framework 2.0 is corrupt and the corrupt file/files remain after you reinstall VS.NET 2005. Hence, please try to uninstall .NET Framework 2.0 and then install .NET Framework 2.0 again.

You can download the “Cleanup_tool” from Aaron's blog to automatically remove the Framework.

Automated cleanup tool to remove the .NET Framework 1.0, 1.1, 2.0, 3.0 and 3.5
http://blogs.msdn.com/astebner/archive/2006/05/30/611355.aspx

Alternately, you can manually do cleanup steps by following another article.

How to manually cleanup a failed .NET Framework 2.0 install
http://blogs.msdn.com/astebner/archive/2005/04/16/408856.aspx

我回头一想，想起昨天在捯饬WCF。对于这个NET 3.5.1给取消了啊

于是。我有勾选上了，再次打开解决方式ok！

不须要重新启动，勾选上就可以！