Duplicate 'Content' items were included. The .NET SDK includes 'Content' items from your project directory by default

Question

Whenever I add a javascript or css file to my asp.net core project and I execute dotnet run in my bash terminal, I get the following error:

/usr/share/dotnet/sdk/1.0.1/Sdks/Microsoft.NET.Sdk/build/Microsoft

.NET.Sdk.DefaultItems.targets(188,5): error : Duplicate 'Content' items were included. The .NET SDK includes 'Content' items from your project directory by default. You can either remove these items from your project file, or set the 'EnableDefaultContentItems' property to 'false' if you want to explicitly include them in your project file. For more information, see https://aka.ms/sdkimplicititems. The duplicate items were: 'wwwroot/css/BasicQuotation.css'; 'wwwroot/js/BasicQuotation.js' [/mnt/c/Dev/myproject/MyProject/MyProject.csproj]

The build failed. Please fix the build errors and run again.

I can fix this by removing the ItemGroup from my csproj file, but I don't think that's very productive.

This happens in the default Visual Studio 2017 ASP.NET Core Web Application (.NET Core) template. I add the files to my project by right clicking the wwwroot > js folder and then select Add > New Item > JavaScript File

This is my .csproj file:

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>netcoreapp1.1</TargetFramework>
  </PropertyGroup>

  <PropertyGroup>
    <PackageTargetFallback>$(PackageTargetFallback);portable-net45+win8+wp8+wpa81;</PackageTargetFallback>
  </PropertyGroup>

  <PropertyGroup>
    <UserSecretsId>aspnet-MyProject-7e1906d8-5dbd-469a-b237-d7a563081253</UserSecretsId>
  </PropertyGroup>

  <ItemGroup>
    <Compile Remove="wwwroot\lib\jquery-validation\**" />
    <Content Remove="wwwroot\lib\jquery-validation\**" />
    <EmbeddedResource Remove="wwwroot\lib\jquery-validation\**" />
    <None Remove="wwwroot\lib\jquery-validation\**" />
  </ItemGroup>

  <ItemGroup>
    <Content Include="wwwroot\css\BasicQuotation.css" />
    <Content Include="wwwroot\js\BasicQuotation.js" />
  </ItemGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Authentication.Cookies" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.2" />
    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="1.1.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="1.1.1" PrivateAssets="All" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="1.1.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer.Design" Version="1.1.1" PrivateAssets="All" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="1.1.0" PrivateAssets="All" />
    <PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="1.1.1" />
    <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="1.1.1" />
    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="1.1.0" PrivateAssets="All" />
  </ItemGroup>
  <ItemGroup>
    <DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="1.0.0" />
    <DotNetCliToolReference Include="Microsoft.Extensions.SecretManager.Tools" Version="1.0.0" />
    <DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="1.0.0" />
  </ItemGroup>
  <ItemGroup>
    <Folder Include="Data\Commands\" />
    <Folder Include="Data\Queries\" />
    <Folder Include="wwwroot\images\" />
  </ItemGroup>

</Project>

If you are running into this problem after updating VS2017 to v15.3, make sure you take a look [here](https://www.danielcrabtree.com/blog/273/fixing-the-duplicate-content-error-after-upgrading-visual-studio-2017). MS decided to include certain folders such as wwwroot by default now, which means they probably are included twice. — jao, Aug 17 '17 at 06:17
The article that @jao shared, explains very well why this happens and how to fix it. Just go straight to that article. — Pepito Fernandez, Aug 28 '17 at 15:11
For more info on `EnableDefaultContentItems`: https://stackoverflow.com/a/46984128/67824 — Ohad Schneider, May 24 '21 at 19:13

score 224 · Answer 1 · edited Mar 01 '19 at 08:22

224

1. Click 'Show All Files' in Solution Explorer
2. Right-click over 'wwwroot' select 'Exclude From Project'
3. Right-click over 'wwwroot' select 'Include in Project'

edited Mar 01 '19 at 08:22

ArunPratap

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answered Aug 17 '17 at 07:46

Dzhefer

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Doing this solved the problem for me, but what actually happened to make it work? – Rono Aug 30 '17 at 14:49
@Rono Looks like it explicitly identifies all the files in your wwwroot file in the .csproj file. eg: https://i.imgur.com/4SPnQ5h.png – J. Schei Sep 01 '17 at 20:18
5

Worked for me as well - and a far more safe way to go in my opinion than the accepted answer. – brinch Sep 12 '17 at 06:09
It worked for me too! Disabling DefaultContentItems helped build my solution, but images, CSSs and other files were not showing. – Bruno Serrano Sep 14 '17 at 17:01
Works! You might have to close and re-open the Solution Explorer in order to make the wwwroot folder visible again after step 2. – Lorentz Sep 21 '17 at 13:45
2

Once you exclude "wwwroot", you might have to click the "Show All Files" button (which looks like 3 sheets of paper messily stacked) at the top of the Solution Explorer to see the "wwwroot" folder so you can add it back in. Mine disappeared and I didn't know how to get it back until I found this button. The folder will look greyed out to indicate it's not included. – James Toomey Mar 15 '19 at 18:04
On VS2019 for Mac, I had to do a "Remove (⌘+⌫)", making sure to not delete the files when asked, and then "Include in project", which worked perfectly! – Louis Waweru Aug 03 '19 at 04:21
Worked like a charm for me too. What I encountered was I had manually edited the .csproj file when I was publishing to IIS, to Include everything in wwwroot like so: published my profile, had all css and js everything was ok. Next time I open my solution, project was unloaded, and could not reload because of duplicate content. Your solution is what worked for me. – SoftDev30_15 Nov 03 '19 at 07:31
What this does is just remove the includes from the project file. So it is the same answer as the accepted answer, just with an different way to reach the same result. – Svenmarim Mar 10 '20 at 13:39
Great answer to an insane problem. I'm struggling to like dotnetcore at the moment – Matt Mar 25 '20 at 13:57

Pinski · Accepted Answer · 2017-08-15T19:00:07.560

So I ran into this same issue. I didn't want to turn off DefaultCompileItems because I knew that wouldn't "fix" the problem. So I unloaded my project and opened the .csproj file in text mode in Visual Studio and saw this.

<ItemGroup>
    <Content Include="wwwroot\css\custom-bootstrap-navbar.css" />
    <Content Include="wwwroot\images\friends-eating\image1.jpg" />
    <Content Include="wwwroot\images\friends-eating\image2.jpg" />
    <Content Include="wwwroot\images\friends-eating\image3.jpg" />
</ItemGroup>
<ItemGroup>
    <Folder Include="wwwroot\images\friends-eating\" />
</ItemGroup>

When I commented out the first ItemGroup block, it worked. What I assume is happening is that the project is adding the entire \images\friends-eating\ folder and then adding each individual image, causing a duplication.

As far as the custom css and js, the project automatically adds wwwroot\css and wwwroot\js so if you have an individual file added (like wwwroot\css\custom-bootstrap-navbar.css) it'll count as a duplicate.

This `` works for me, but visual studio undo that later on :( — Jaider, Oct 01 '17 at 12:59
Ok so I don't get it. What the hell is visual studio actually doing and why? — tnk479, May 29 '19 at 02:00

score 35 · Answer 3 · answered Jun 05 '17 at 03:44

35

This worked in my case:

 <PropertyGroup>
    ...
    <EnableDefaultContentItems>false</EnableDefaultContentItems>
  </PropertyGroup>

answered Jun 05 '17 at 03:44

Sith2021

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As stated in my comment to Pinki's answer, I would not propose this as solution as this could lead to more errors. – Matt Aug 15 '17 at 14:53
I actually ran into bigger problems setting this option to false. I would also recommend not setting it to false. – Rwiti Dec 07 '17 at 18:47
What's the cleanest way to get a Folder to be included entirely as EmbeddedResource elements? – John Zabroski Feb 12 '19 at 15:50
After this wwwroot wasn't included any longer. So better don't use this... – UNeverNo May 13 '19 at 14:46

Dmitry · Answer 4 · 2017-08-17T08:02:38.260

17

As link says, you can disable this behavior (auto-include) and include all content explicitly by adding this into your csproj file:

<PropertyGroup>
    <EnableDefaultContentItems>false</EnableDefaultContentItems>
</PropertyGroup>

edited Aug 17 '17 at 08:02

answered Apr 10 '17 at 15:18

Dmitry

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When I add that to my csproj file and I remove the css/js itemgroup, I get the following error: `CSC : error CS5001: Program does not contain a static 'Main' method suitable for an entry point [/mnt/c/Dev/myproject/MyProject/MyProject.csproj] The build failed. Please fix the build errors and run again.` – jao Apr 10 '17 at 16:49
2

"Content" not "Compile" - Doesn't it? – Sith2021 Jun 05 '17 at 03:47
One side note....if you don't explicitly include your Views folder, it won't publish your views with this setting – saluce Aug 21 '17 at 19:02
1

I tried this but it didn't work. still getting the same error – pantonis Aug 31 '17 at 06:34

score 17 · Answer 5 · edited Dec 11 '17 at 21:38

17

It happend when I upgrade my project from .NET Core 1.X to 2.0 just now. Here is my solution.

Open xxx.csproj, or right click project
Unload Project
Edit xxx.csproj.

Then remove ItemGroup items start with <Content Include = "wwwroot\xxxxx"

edited Dec 11 '17 at 21:38

usefulBee

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answered Aug 15 '17 at 10:01

wtf512

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Thanks! Note: It seems to be related to latest Visual Studio version 15.3, not directly to .NET Core 2.0 – Vincent V. Aug 21 '17 at 08:29

score 10 · Answer 6 · answered Jun 30 '17 at 18:20

My issues was close but not the exact same. My error was this:

C:\Program Files\dotnet\sdk\2.0.0-preview2-006497\Sdks\Microsoft.NET.Sdk\build\Microsoft.NET.Sdk.DefaultItems.targets(285,5): error : Duplicate 'Content' items were included. The .NET SDK includes 'Content' items from your project directory by default. You can either remove these items from your project file, or set the 'EnableDefaultContentItems' property to 'false' if you want to explicitly include them in your project file. For more information, see https://aka.ms/sdkimplicititems. The duplicate items were: 'wwwroot\js\KOBindings.js'; 'wwwroot\js\KOPleaseWait.js'; 'wwwroot\js\ProjectTime\Add.js'; 'wwwroot\js\TimeAdmin\Invoice.js'; 'wwwroot\js\TimeAdmin\PayPeriodTotals.js' [C:\Avantia Projects\Time Card\avantia-timesheet\Solution\Almanac\Almanac.csproj]

If I did this:

<EnableDefaultContentItems>false</EnableDefaultContentItems>

It would not compile as all of the sudden Areas would not be recognized.

My solution, seems odd, but the message is telling me so, there were duplicate files:

The duplicate items were: 'wwwroot\js\KOBindings.js'; 'wwwroot\js\KOPleaseWait.js'; 'wwwroot\js\ProjectTime\Add.js'; 'wwwroot\js\TimeAdmin\Invoice.js'; 'wwwroot\js\TimeAdmin\PayPeriodTotals.js'

Looking at my .csproj file:

<ItemGroup>
  <Content Include="pdf.js" />
  <Content Include="wwwroot\js\package.json" />
  <Content Include="wwwroot\js\pdf.js" />
  <Content Include="wwwroot\js\KOBindings.js" />
  <Content Include="wwwroot\js\KOPleaseWait.js" />
  <Content Include="wwwroot\js\ProjectTime\Add.js" />
  <Content Include="wwwroot\js\TimeAdmin\Invoice.js" />
  <Content Include="wwwroot\js\TimeAdmin\PayPeriodTotals.js" />
</ItemGroup>

This was the ONLY location within the entire project where these files were references (aside from where they were loaded.) So the phrase duplicate does not make any sense to me. However, commenting those files out as such, took care of my problem:

<ItemGroup>
  <Content Include="pdf.js" />
  <Content Include="wwwroot\js\package.json" />
  <Content Include="wwwroot\js\pdf.js" />
  <!--
    <Content Include="wwwroot\js\KOBindings.js" />
    <Content Include="wwwroot\js\KOPleaseWait.js" />
    <Content Include="wwwroot\js\ProjectTime\Add.js" />
    <Content Include="wwwroot\js\TimeAdmin\Invoice.js" />
    <Content Include="wwwroot\js\TimeAdmin\PayPeriodTotals.js" />
  -->
</ItemGroup>

I assume this has something to do with the 2.0.0-preview2-006497 that I recently installed.

Also, this link mentions talks about globs. But does not tell me where that is. It talks about SDKs and such. Yet the answer was my custom .js files. That link needs to be updated or expanded on IMHO. Hope this helps someone.

Would love to know why this works. However, just worked for me. =) — Frog Pr1nce, Aug 31 '17 at 18:10

score 4 · Answer 7 · answered Oct 19 '21 at 12:58

4

So what worked for me was clicking on the file in question in the Solution Explorer and choosing "Exclude from Project". Then re-add it back using "Include in Project".

answered Oct 19 '21 at 12:58

Chris

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score 3 · Answer 8 · answered Apr 11 '17 at 07:50

3

Not that I can see it in your example above, to help other SO searchers..

You can also get this error when you have the same file listed twice in <Content Include="xxx" /> elements in your csproj file.

Remove the duplicate and rebuild.

answered Apr 11 '17 at 07:50

Sam

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score 3 · Answer 9 · answered Aug 15 '17 at 11:47

3

In my case, I solved this by deleting all files from the wwwroot-Directory in VS. Unload and reload the Project. Copy all files back in with VS. Done

answered Aug 15 '17 at 11:47

Alex Freund

31
4

None of the top solutions worked for me I did this before reading your comment and this works flawless!!! I excluded the wwwroot, controllers, views folders and added them back and now everything works fine! – revobtz Aug 16 '17 at 19:09

score 3 · Answer 10 · answered Aug 15 '17 at 12:34

3

Actually, Asp.net core automatically include content from wwwroot\css\ , wwwroot\js\ and wwwroot\lib\ location, so despite this if your csproj file explicitly include content from those directories then those content will be duplicated so removing content from you csproj file is the better way to get rid of this error. So remove below content-

  <ItemGroup>
    <Compile Remove="wwwroot\lib\jquery-validation\**" />
    <Content Remove="wwwroot\lib\jquery-validation\**" />
    <EmbeddedResource Remove="wwwroot\lib\jquery-validation\**" />
    <None Remove="wwwroot\lib\jquery-validation\**" />   
 </ItemGroup>

  <ItemGroup>
    <Content Include="wwwroot\css\BasicQuotation.css" />
    <Content Include="wwwroot\js\BasicQuotation.js" />   
  </ItemGroup>

answered Aug 15 '17 at 12:34

Mostafiz

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This happened to me on updating Visual Studio to 15.3. To prevent breaking changes to my colleagues who have not updated yet, I had to add ` false ` to the .csproj file. – saluce Aug 17 '17 at 18:41
@saluce yes you are right, the same solution you can use in your context too. the choice is based on the developer whether he wants to keep `EnableDefaultContentItems` or not. They are two different approach – Mostafiz Aug 18 '17 at 08:48
My point was that the only change I made was upgrading Visual Studio to 15.3. I made no changes to my project, but prior to the upgrade, this setting was not required. – saluce Aug 19 '17 at 21:25

score 3 · Answer 11 · answered Nov 06 '17 at 11:14

.NET Core Projects

If you are in a class library, probably you'll need to remove all Compile/Content elements from your csproj as those are included automatically.

<Project Sdk="Microsoft.NET.Sdk">    
  <PropertyGroup>
    <TargetFramework>netcoreapp2.0</TargetFramework>
  </PropertyGroup>
  <!-- NEEDED -->
  <ItemGroup>
    <ProjectReference />
    <ProjectReference />
  </ItemGroup>
  <!-- NOT NEEDED -->
  <ItemGroup>
   <Compile Include="Models\ExampleClass.cs" />
   <Content ... />
  </ItemGroup>
</Project>

Duy Hoang · Answer 12 · 2019-03-08T01:02:27.013

3

My case I is disable both below default items.

<EnableDefaultContentItems>false</EnableDefaultContentItems>
<EnableDefaultItems>false</EnableDefaultItems>

edited Mar 08 '19 at 01:02

answered Nov 13 '18 at 03:00

Duy Hoang

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Kyriacos · Answer 13 · 2017-08-14T21:47:16.700

2

Under Visual Studio 2017 15.3, with .NET Core 2.0, EnableDefaultCompileItems did not work for me.

I needed to add this to my .csproj

  <PropertyGroup>
    <EnableDefaultContentItems>false</EnableDefaultContentItems>
  </PropertyGroup>

edited Aug 14 '17 at 21:47

answered Aug 09 '17 at 09:04

Kyriacos

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For me (visual studio 15.3.4 .NET framework 4.5.2) EnableDefaultContentItems did not work while EnableDefaultCompileItems did. – hlovdal Sep 13 '17 at 12:00

score 1 · Answer 14 · answered Aug 19 '17 at 14:08

I found a different proper solution.

Right click on your mvc project and click Edit csproj.
If you are adding files under wwwroot, just move them to a folder under wwwroot, let's say it "theme"

And delete all content tags in csproj file if their exists, an example;

<Content Include="wwwroot\theme\favicon.ico" />
<Content Include="wwwroot\theme\fonts\cyrillic-ext400.woff2" />
<Content Include="wwwroot\theme\fonts\cyrillic-ext700.woff2" />

And only add this;

  <ItemGroup>
    <Folder Include="wwwroot\theme\" />
  </ItemGroup>

So, csproj file should be look like this;

    <Project Sdk="Microsoft.NET.Sdk.Web">

      <PropertyGroup>
        <TargetFramework>netcoreapp1.1</TargetFramework>
      </PropertyGroup>

      <PropertyGroup>
        <PackageTargetFallback>$(PackageTargetFallback);portable-net45+win8+wp8+wpa81;</PackageTargetFallback>
      </PropertyGroup>

      <ItemGroup>
        <Folder Include="wwwroot\theme\" />
      </ItemGroup>
      <ItemGroup>
        <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.0.0" />
...

With that way, I think you are adding all files under theme folder. So not include them one by one which occours some erros.

score 1 · Answer 15 · answered Dec 17 '21 at 23:11

All of the answers that were written before me did not resolve the 'Duplicate' errors for me, even though I had taken the due diligence to ensure their recommended procedures were followed.

For me, the 'Duplicate content' issue occurred when I tried to upgrade my WinUI 3 Application's SDK from Windows App SDK 0.8 to 1.0 in the Nuget Package Manager. When I did this, my project began to produce this error on every compile, and I tried to do the Exclude/Include methods that other suggested, but to no avail.

It took me about eight hours to find the culprit, which was a reference to another WinUI library project that I still had on Windows App SDK 0.8. Once I upgraded the other WinUI library project to SDK 1.0, this error went away.

Leaving this answer here in case it helps anyone else.

score 0 · Answer 16 · answered Aug 16 '17 at 19:11

0

Excluding and Including back the folders that have duplicates error worked for me! Hope this helps someone else!

answered Aug 16 '17 at 19:11

revobtz

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score 0 · Answer 17 · edited Aug 17 '17 at 11:11

0

I think what disabling "EnableDefaultContentItems" isn't the best option. Manual cs-Proj file editing also isn't the good idea at all.

So for our build server pipeline, we wrote very small tool what will remove all duplicated entries automatically: dotnet-csproj-cleaner

We run it under Docker as the first build step in our continuous integration pipeline.

edited Aug 17 '17 at 11:11

always-a-learner

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answered Aug 17 '17 at 10:15

anakod

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Seems nice but why is it limited to projects with a wwwroot path? – John Zabroski Feb 12 '19 at 15:56
It's standard VS content location and it's path included by default. If you need more complex solution - please feel free to submit pull request. It should be very easy by adding additional command line arguments. Thank you. – anakod Jul 25 '19 at 12:17

score 0 · Answer 18 · answered Jun 11 '18 at 17:01

I had the same problem with only a file, and all others were working (all my templates were stored directly in wwwroot/content). The project was not created by me so I don't know many details.

The problem was fixed by renaming back and forth the file with the issue:

MyTemplate.html -- renamed --> MyTemplate2.html -- renamed --> MyTemplate.html

Note: At the first rename I got an error with something along the lines of "content configuration not found", but the second rename worked without issues.

After this I was able to compile the project successfully.

score 0 · Answer 19 · answered Apr 30 '21 at 21:41

0

I'm just getting started and I had this error when I tried copying a wwwroot folder from a Web Application template to a project created with an API template. removing bootstrap solved it for me, which is fine because I just need jquery.

answered Apr 30 '21 at 21:41

Adnan

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sbeaudoin · Answer 20 · 2022-07-07T22:54:35.493

0

It happened to me on a new WinUI project in .Net 6 only when I referenced an old WinUI component. I solved it and many other unsolvable errors (InitalizeComponent not found for example) by doing the following on the old WinUI component :

Remove the following packages

Replace it with :

edited Jul 07 '22 at 22:54

answered Jul 07 '22 at 22:47

sbeaudoin

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score 0 · Answer 21 · answered Aug 09 '22 at 12:00

0

for .net core 6.0 this solved:

add to .csproj file

 <ItemGroup>
   <Content Update="wwwroot\**\*">
     <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
   </Content>
 </ItemGroup>

answered Aug 09 '22 at 12:00

NoWhereToBeSeen

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score 0 · Answer 22 · answered Sep 05 '22 at 13:07

0

I had renamed one of my class files in Visual Studio for Mac which I could see the edits for when checking the git changes for the project file. Removing the file and adding it back to the project fixed the problem.

answered Sep 05 '22 at 13:07

James Westgate

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Duplicate 'Content' items were included. The .NET SDK includes 'Content' items from your project directory by default

22 Answers22

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