我使用VSO/Azure DevOps。

您也可以直接在浏览器中访问提要url。你最终可能会得到这样的回复，这可能会让你的诊断更快:

用户没有使用ms.feed扩展名的许可证。

去

设置(PC全局设置)>网络和Internet >代理>自动代理设置>和“自动检测设置”设置为“关闭”。

我删除了%localappdata%/Nuget中的所有内容，并清除了NuGets缓存。

dotnet nuget locals all --clear

重新启动后，Visual studio 2022恢复了我的包。

有些开发环境可能既不使用浏览器也不使用代理。

一种解决方案是从nugget(例如https://dotnet.myget.org/F/dotnet-core/api/v3/index.json)下载包到共享目录，然后执行以下操作:

dotnet add package Microsoft.AspNetCore.StaticFiles -s "shared drive:\index.json"

我希望这对你有用。  

I had the same error message while scaffolding Identity to my ASP.NET Core MVC project. Since my connection was not behind a proxy, removing/editing proxy configurations didn't make sense. And I didn't want to delete a file or uninstall PMC either. While looking around I realized a "Clear All Nuget Cache(s)" button on Tools --> Options --> NuGet Package Manager --> General. After pressing the button I had to wait for some time for the operation to complete. After that I tried to scaffold the Identity again but it didn't work. Then I decided to restart VS and voila :)

我在Visual Studio 2015上执行Install-Package Modernizr时遇到了类似的问题。我通过以下步骤解决了这个问题:

Download the package from its online source. Go to Tools/NuGet Package Manager/Package Manager Settings. Select Package Sources from the window. Add a new package source by clicking on the + sign. Enter a name and source location by clicking on ... (triple dot) sign. Make sure that only the package source that you've just added is checked. Uncheck all the other package sources. Go to Package Manager Console and type Install-Package Modernizr. Visual Studio 2015 installs the package automatically and creates Scripts and packages folders in your root folder.

我希望同样的解决方案在安装其他包时也能起作用。