I am experiencing the following NU1605 dependency errors in my **netcoreapp2.0** console application:

```
NU1605  Detected package downgrade: System.Diagnostics.Debug from 4.3.0 to 4.0.11. Reference the package directly from the project to select a different version. 
 MyProject -> Colorful.Console 1.2.6 -> System.IO.FileSystem 4.0.1 -> runtime.win.System.IO.FileSystem 4.3.0 -> System.Diagnostics.Debug (>= 4.3.0) 
 MyProject -> System.Diagnostics.Debug (>= 4.0.11)

NU1605  Detected package downgrade: System.Runtime.Extensions from 4.3.0 to 4.1.0. Reference the package directly from the project to select a different version. 
 MyProject -> Colorful.Console 1.2.6 -> System.IO.FileSystem 4.0.1 -> runtime.win.System.IO.FileSystem 4.3.0 -> System.Runtime.Extensions (>= 4.3.0) 
 MyProject -> Colorful.Console 1.2.6 -> System.Runtime.Extensions (>= 4.1.0)    MyProject

NU1605  Detected package downgrade: System.Runtime.Handles from 4.3.0 to 4.0.1. Reference the package directly from the project to select a different version. 
 MyProject -> Colorful.Console 1.2.6 -> System.IO.FileSystem 4.0.1 -> runtime.win.System.IO.FileSystem 4.3.0 -> System.Runtime.Handles (>= 4.3.0) 
 MyProject -> Colorful.Console 1.2.6 -> System.IO.FileSystem 4.0.1 -> System.Runtime.Handles (>= 4.0.1)

NU1605  Detected package downgrade: System.Runtime.InteropServices from 4.3.0 to 4.1.0. Reference the package directly from the project to select a different version. 
 MyProject -> Colorful.Console 1.2.6 -> System.Console 4.0.0 -> runtime.win.System.Console 4.3.0 -> System.Runtime.InteropServices (>= 4.3.0) 
 MyProject -> Colorful.Console 1.2.6 -> System.Runtime.InteropServices (>= 4.1.0)

```

I have tried referencing these package versions in csproj, but this doesn't fix the problem. See csproj:

```
<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.0</TargetFramework>
    <RuntimeIdentifier>win10-x64</RuntimeIdentifier>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Colorful.Console" Version="1.2.6" />
    <PackageReference Include="CommandLineParser" Version="2.2.1" />
    <PackageReference Include="DotSpinners" Version="1.2.0" />
    <PackageReference Include="System.Diagnostics.Debug" Version="4.0.11" />
    <PackageReference Include="System.Runtime.Extensions" Version="4.1.0" />
    <PackageReference Include="System.Runtime.Handles" Version="4.0.1" />
    <PackageReference Include="System.Runtime.InteropServices" Version="4.1.0" />
  </ItemGroup>
</Project>

```

And they do seem to restore fine:

[![Package References](https://i.stack.imgur.com/RhyLG.png)](https://i.stack.imgur.com/RhyLG.png)

The project is also referencing the **Microsoft.NETCore.App 2.0** SDK.

When performing dotnet restore from the CLI, I also get the following error, which I am not sure is related:

```
C:\Program Files\dotnet\sdk\2.1.200\NuGet.targets(114,5): error : Failed to retrieve information about 'System.Runtime.Serialization.Formatters' from remote source 'https://mycompany.pkgs.visualstudio.com/_packaging/myid/nuget/v3/flat2/system.runtime.serialization.formatters/index.json'. [C:\MyProject\MyProject.sln]
C:\Program Files\dotnet\sdk\2.1.200\NuGet.targets(114,5): error : Response status code does not indicate success: 401 (Unauthorized). [C:\MyProject\MyProject.sln]

```

I have no idea why it's trying to retrieve information about 'System.Runtime.Serialization.Formatters' from our private company package repository. 

**NuGet.config:**

```
<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <packageSources>
    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
    <add key="mycompany" value="https://mycompany.pkgs.visualstudio.com/_packaging/Stable/nuget/v3/index.json" />
  </packageSources>
  <packageSourceCredentials>
     <mycompany>
       <add key="Username" value="vsts" />
       <add key="ClearTextPassword" value="xxx" />
     </mycompany>
   </packageSourceCredentials>
  <disabledPackageSources>
    <add key="Microsoft and .NET" value="true" />
  </disabledPackageSources>
  <packageRestore>
    <add key="enabled" value="True" />
    <add key="automatic" value="True" />
  </packageRestore>
  <bindingRedirects>
    <add key="skip" value="False" />
  </bindingRedirects>
  <packageManagement>
    <add key="format" value="0" />
    <add key="disabled" value="False" />
  </packageManagement>
</configuration>

```

I also have the following NU1603 warning if this means anything:

```
NU1603  MyProject depends on System.Runtime.Handles (>= 4.1.0) but System.Runtime.Handles 4.1.0 was not found. An approximate best match of System.Runtime.Handles 4.3.0 was resolved.

```