Installing Ext.NET via nuget error: 'Newtonsoft.Json' already has a dependency defined for 'Microsoft.CSharp' - visual-studio

Question

I am trying to install Ext.NET on Visual Studio 2012 via Package Manager Console but I receive this error:
'Newtonsoft.Json' already has a dependency defined for
'Microsoft.CSharp'
Here is the full process:
Install-Package Ext.NET
Attempting to resolve dependency 'Ext.NET.Utilities (≥ 2.5.0)'.
Attempting to resolve dependency 'Transformer.NET (≥ 2.1.1)'.
Attempting to resolve dependency 'Newtonsoft.Json (≥ 10.0.2)'.
Install-Package : 'Newtonsoft.Json' already has a dependency defined for 'Microsoft.CSharp'.
At line:1 char:1
+ Install-Package Ext.NET
+ ~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Install-Package], InvalidOperationException
+ FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PowerShell.Commands.InstallPackageCommand
*Nuget version: 2.8.60318.667

Answer 1

What Matt Ward said is perfectly correct. You can notice that one dependency restriction for package Ext.NET is Newtonsoft.Json (>= 10.0.2):
There is a dependency restriction for .NETStandard 1.0 framework of Newtonsoft.Json: Microsoft.CSharp (>= 4.3.0), you can check it from Json.NET 10.0.2. However, NuGet not support the newer .NETStandard frameworks until NuGet 2.12, you can get this information from NuGet release note 2.12.
Full NetStandard and NetCoreApp support for VS2013.
We could not use NuGet 2.12 on the Visual Studio 2012, so to resolve this issue, you can update your Visual Studio 2012 to Visual Studio 2013 or manage that assembly Manually, but this will bring a lot of tasks.