我知道这个问题很老了，但是我今天遇到了同样的情况，我想为最近发现这个问题的人提供我的2美分。我手动移动到解决方案中的一个子文件夹，然后使用Visual Studio 2017删除并读取到解决方案的一个ASP MVC项目给出了上述错误。移动“lib”和“packages”文件夹到同一子文件夹的根MVC项目修复了我的问题。

Not sure if this will help anyone, but I had this issue come up when I deleted the source code from my local machine without having ever saved the solution file to TFS. (During initial development, I was right-clicking and checking in the project in Solution Explorer, but forgot to ever check in the solution itself.) When I needed to work on this again, all I had in TFS was the .csproj file, no .sln file. So in VS I did a File --> Source Control --> Advanced -- Open from Server and opened the .csproj file. From there I did a Save All and it asked me where I wanted to save the .sln file. I was saving this .sln file to the project directory with the other folders (App_Data, App_Start, etc.), not the top level directory. I finally figured out that I need to save the .sln file up a directory from the project folder so it's on the same level as the project folder. All my paths resolved and I was able to build it again.

我正在使用VS2012，遇到同样的错误。我从.csproj文件中删除了下面的Target标记，它开始编译，没有出现任何错误。

<Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
  -- Error messages within Target Tag
</Target>

您还可以使用建议的错误消息作为提示。下面是如何找到解决方案的管理包，并单击解决丢失的nuget包。

就是这样

注释掉.csproj中的以下代码

<Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
<PropertyGroup>
  <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
</PropertyGroup>
<Error Condition="!Exists('..\packages\Costura.Fody.2.0.1\build\Costura.Fody.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Costura.Fody.2.0.1\build\Costura.Fody.targets'))" />
<Error Condition="!Exists('..\packages\Fody.3.1.3\build\Fody.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Fody.3.1.3\build\Fody.targets'))" />

遇到这个问题

按以下步骤求解

清除packages文件夹中的内容(先备份) 使用“更新-包-重新安装”从包管理控制台的NuGet中重新获取和重新安装包(Tools -> NuGet包管理器->包管理控制台) 从.csproj文件中删除冗余路径。注意:NuGet会添加新的路径到csproj文件，但它不会删除旧的路径… (有一些机会csproj文件有多个路径为同一文件)

为什么我们需要“Microsoft.Net.Compilers.props”? 它将提供“\roslyn”文件夹。如果没有它，你可能仍然可以编译程序，但不能使用@{html.RenderPartial…}