VS2017 - Project load failed - Duplicated linked item found in the project - asp.net-core

Question

I'm unable to get my project to load if an included Nuget package includes files that exist in my project.
My Nuget package contains a appsettings.json file, and since my project also has an appsettings.json file, I get the following error in Visual Studio 2017:
(load failed) - Duplicated linked item found in the project: "C:\users\user\.nuget\packages\mypackage\contentFiles\any\netcoreapp1.1\appsettings.json"
If I remove the appsettings file from my project (not the Nuget package), the project loads fine, but the file is needed for the project to work.
I can't seem to remove the appsettings file from the nuget package, but this might be my only option.
'dotnet pack' seems to include this file even though my csproj file is not referencing it in the "CopyToPublishDirectory"
So the question is:
How to exclude certain files from being packaged (via dotnet pack)?
Or how to load a project where duplicated linked items exist?

Answer 1

My set up is different from yours, but I got a similar error message when trying to add an existing project to a solution. I tried a few things, so not sure what exactly helped solved it in the end, but here's what I did:
Cleaned the folder in which the project was located by deleting bin and obj folders
Noticed that in the csproj file of the failing to load project there were a couple of PropertyGroup and Item nodes that were not used or were empty or pointing to folders that were not on the disk anymore, so I removed those nodes.
After that I removed and re-added the project to the solution and it loaded successfully.

Answer 2

I managed to get it to work.
By default all content files are packaged.
To disable this I edited the csproj file as follows:
<PropertyGroup>
<EnableDefaultContentItems>false</EnableDefaultContentItems>
</PropertyGroup>
<ItemGroup>
<Content Include="appsettings.*">
<Pack>false</Pack>
</Content>
<ItemGroup>

Answer 3

This seems to be happening (among possibly other things) in projects which reference another project where there's a shared reference between the two.
For example:
Parent project [references package/dll X]
|
*-> Child, failing project [also explicitly references package/dll X]
In my case removing the X reference from the failed project helped solve the problem.

Answer 4

Had a similar issue, originally, clone to a new location fixed it. After it came bay I noticed in the csproj file
<ItemGroup>
<Folder Include="Helpers\" />
<Folder Include="Styles\" />
<Folder Include="Services\Interfaces\" />
<Folder Include="Controls\" />
<Folder Include="Styles\Fonts\" />
<Folder Include="ViewModels\Base\" />
<Folder Include="ViewModels\Product" />
<Folder Include="ViewModels\Invoice\" />
<Folder Include="ViewModels\Product\" />
<Folder Include="Views\Product\Popup\" />
</ItemGroup>
ViewModels\Product was referenced twice.