This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=317567.

记事本打开csproj文件

搜索nuget 删除Target节点 类似如下:

<Target Name="EnsureBclBuildImported" BeforeTargets="BeforeBuild" Condition="'$(BclBuildImported)' == ''">
<Error Condition="!Exists('..WindowFormDemopackagesMicrosoft.Bcl.Build.1.0.14 oolsMicrosoft.Bcl.Build.targets')" Text="This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them. For more information, see http://go.microsoft.com/fwlink/?LinkID=317567." HelpKeyword="BCLBUILD2001" />
<Error Condition="Exists('..WindowFormDemopackagesMicrosoft.Bcl.Build.1.0.14 oolsMicrosoft.Bcl.Build.targets')" Text="The build restored NuGet packages. Build the project again to include these packages in the build. For more information, see http://go.microsoft.com/fwlink/?LinkID=317568." HelpKeyword="BCLBUILD2002" />
</Target>

其他解决方案

参考：http://docs.nuget.org/ndocs/consume-packages/package-restore

找到 项目文件.csproj，打开后，移除下面的内容

<Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
  <PropertyGroup>
    <ErrorText>This project references NuGet package(s) that are missing on this computer. Enable 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('$(SolutionDir).nugetNuGet.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir).nugetNuGet.targets'))" />
</Target>

https://www.cnblogs.com/slwangzi/p/6082330.html