VSO Build not able to download packages - nuget

Question

I have the following nuget.config file and bellow is the file content
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<config>
<add key="repositoryPath" value="Packages" />
</config>
<packageRestore>
<add key="enabled" value="True" />
</packageRestore>
<packageSources>
<!-- Ditch all the Global NuGet package sources we only want a
single private NuGet repo for this project -->
<clear />
<add key="private="private" />
<add key="nuget.org" value="https://www.nuget.org/api/v2/" />
</packageSources>
<disabledPackageSources>
<add key="nuget.org" value="false" />
</disabledPackageSources>
</configuration>
All the packages which exist in the private feed are restored but the same is not happening with the ones in nuget.org:
From VSO build output
Feeds used:
C:\Users\buildguest\AppData\Local\NuGet\Cache
private
https://www.nuget.org/api/v2/
...
Restoring NuGet package AutoMapper.5.2.0.
WARNING: Unable to find version '5.2.0' of package 'AutoMapper'.
This is happening during the NuGet restore step in VSO.

Answer 1

Use NuGet.Protocol.Core.v3 feed protocol with
<add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
instead of
<add key="nuget.org" value="https://nuget.org/api/v2/" />

Answer 2

enter image description here
Inside Nuget.config put the bellow code.
<configuration>
<packageRestore>
<add key="enabled" value="True"/>
<add key="automatic" value="True"/>
</packageRestore>
</configuration>