Payload contains two or more files with the same destination path - visual-studio

Question

I created a new UWP MSTest Project and I added a reference to my main application. When I build the solution, get the an error:
Payload contains two or more files with the same destination path
Along with the conflicting files. I checked the copy to local for the files and they are set to Do not copy. Here's a sample of the error messages:
Severity Code Description Project File Line Suppression State
Error Payload contains two or more files with the same destination
path 'Assets\Square44x44Logo.targetsize-24_altform-unplated.png'.
Source files:
C:\Users\joe.nuget\packages\newtonsoft.json\11.0.1-beta1\lib\netstandard2.0\Newtonsoft.Json.dll
C:\Program Files (x86)\Microsoft SDKs\Windows
Kits\10\ExtensionSDKs\TestPlatform.Universal\15.5\Redist\CommonConfiguration\neutral\Newtonsoft.Json.dll App.Test C:\Program
Files (x86)\Microsoft Visual
Studio\2017\Community\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets 1747
Error Payload contains two or more files with the same destination
path 'Assets\Wide310x150Logo.scale-200.png'. Source files:
E:\App.Test\Assets\Wide310x150Logo.scale-200.png
E:\App\Assets\Wide310x150Logo.scale-200.png App.Test C:\Program Files
(x86)\Microsoft Visual
Studio\2017\Community\MSBuild\Microsoft\VisualStudio\v15.0\AppxPackage\Microsoft.AppXPackage.Targets 1747

Answer 1

This happens when the content file names are the same for the app itself and the test project. Even though you set them to Do not copy, they are still conflicting during the intermediate step of building the test project.
The simplest solution is to rename or delete the Asset PNGs inside the Test Project so that they do not conflict with your app itself.
Newtonsoft.Json
Problem with Newtonsoft.Json is a known issue that has been reported to the Visual Studio team and the fix is now pending release.
The only workaround mentioned is the following by Morten Nielsen:
As a workaround and if you can live with the v9 version the test
project ships with, you can add a direct assembly reference to the
Json.net lib that they use, instead of using the nuget reference.