all packages referring NuGetVersionRoslyn 3.4.0-beta4-19568-04 give error
package not found

cause they are unlisted on https://pkgs.dev.azure.com/azure-public/vside/_packaging/vssdk/nuget/v3/index.json

lowest version of
microsoft.codeanalysis.editorfeatures
is 3.8.0-1.20351.8 now on https://pkgs.dev.azure.com/azure-public/vside/_packaging/vssdk/nuget/v3/index.json

remark:
version 3.4.0-beta4-19568-04 was maybe build from
dotnet/roslyn@82f2e25 Tag: Visual-Studio-2019-Version-16.4