Unable to load the service index for source https://www.myget.org/F/aspnetcidev/api/v3/index.json

Describe the bug

We have a reference to aspnetcidev in our project that is currently failing to load with a 404. This was working on December 16 (example successful build), but is failing now (example failing build built off the same commit).

To Reproduce

I have an Azure Pipelines build reproing the problem here - https://dev.azure.com/mseng/PipelineTools/_build/results?buildId=14071349&view=results.

The repro itself should be as simple as adding a line like this to any project https://github.com/microsoft/azure-pipelines-agent/blob/763575e4443b61e2957d60dca9a9e068d29ccd92/src/Test/NuGet.Config#L10

Exceptions (if any)

/home/vsts/work/1/s/_dotnetsdk/3.1.100/sdk/3.1.100/NuGet.targets(123,5): error : Unable to load the service index for source https://www.myget.org/F/aspnetcidev/api/v3/index.json. [/home/vsts/work/1/s/src/Test/Test.csproj] [/home/vsts/work/1/s/src/dir.proj]
/home/vsts/work/1/s/_dotnetsdk/3.1.100/sdk/3.1.100/NuGet.targets(123,5): error : Response status code does not indicate success: 404 (Feed does not exist.). [/home/vsts/work/1/s/src/Test/Test.csproj] [/home/vsts/work/1/s/src/dir.proj]

Further technical details

This is from my local repro (not Azure Pipelines), but it repros there as well

.NET Core SDK (reflecting any global.json):
 Version:   2.2.105
 Commit:    7cecb35b92

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.19042
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\2.2.105\

Host (useful for support):
  Version: 2.2.3
  Commit:  6b8ad509b6

.NET Core SDKs installed:
  2.1.503 [C:\Program Files\dotnet\sdk]
  2.1.511 [C:\Program Files\dotnet\sdk]
  2.1.519 [C:\Program Files\dotnet\sdk]
  2.2.105 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.23 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.2.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.23 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.2.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.23 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.2.3 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]

[amaillo-mc]

Same here, waiting for resolution or workaround…

[BrennanConroy]

A lot of the myget packages are available with the feed “https://pkgs.dev.azure.com/dnceng/public/_packaging/myget-legacy/nuget/v3/index.json”, although we recommend not using it (packages may be removed from that feed at any time without warning), and if there are supported packages that aren’t on NuGet please let us know.

I am looking for the ASP.NET Core version of SignalR.Server, version 0.1.0

Please move off of that package starting 5 years ago, it is super unsupported and half done.