C# – How to diagnose warning MSB3277: Found conflicts between different versions of the same dependent assembly that could not be resolved

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I'm getting an annoying MSB3277 warning when I build my project. I increased verbosity to "detailed" and I was able to get the following information from the log:

      There was a conflict between "Pathoschild.Http.Client, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null" and "Pathoschild.Http.Client, Version=3.1.0.0, Culture=neutral, PublicKeyToken=null".
         "Pathoschild.Http.Client, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null" was chosen because it was primary and "Pathoschild.Http.Client, Version=3.1.0.0, Culture=neutral, PublicKeyToken=null" was not.

         References which depend on "Pathoschild.Http.Client, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null" [C:\Users\desau\.nuget\packages\pathoschild.http.fluentclient\3.0.0\lib\netstandard1.3\Pathoschild.Http.Client.dll].
             C:\Users\desau\.nuget\packages\pathoschild.http.fluentclient\3.0.0\lib\netstandard1.3\Pathoschild.Http.Client.dll
               Project file item includes which caused reference "C:\Users\desau\.nuget\packages\pathoschild.http.fluentclient\3.0.0\lib\netstandard1.3\Pathoschild.Http.Client.dll".
                 C:\Users\desau\.nuget\packages\pathoschild.http.fluentclient\3.0.0\lib\netstandard1.3\Pathoschild.Http.Client.dll

         References which depend on "Pathoschild.Http.Client, Version=3.1.0.0, Culture=neutral, PublicKeyToken=null" [].
             C:\Users\desau\.nuget\packages\stronggrid\0.30.0\lib\netstandard1.3\StrongGrid.dll
               Project file item includes which caused reference "C:\Users\desau\.nuget\packages\stronggrid\0.30.0\lib\netstandard1.3\StrongGrid.dll".
                 C:\Users\desau\.nuget\packages\stronggrid\0.30.0\lib\netstandard1.3\StrongGrid.dll

If I understand this log correctly, it's telling me that my project references Pathoschild.Http.Client version 3.0 and also version 3.1. I understand the reference to version 3.1 because my project references a nuget package called StrongGrid which itself references Pathoschild version 3.1

But I fail to understand where the reference to version 3.0 comes from.

I'm using Visual Studio 2017 and MSBuild 15 in case that's helpful information.

Best Answer

The reason for this issue is that the StrongGrid package is authored incorrectly.

The version 0.30 of StrongGrid is built against version 3.1.0 of Pathoschild.Http.FluentClient, but their .nuspec file used for creating the NuGet package still lists version 3.0.0 as dependency, so the consuming project will fetch an older version, creating a conflict that cannot be resolved.

To work around this problem, you can explicitly reference version 3.1.0 of Pathoschild.Http.FluentClient by adding a package reference to the csproj file to override the version.

Related Solutions

C# – I get a “An attempt was made to load a program with an incorrect format” error on a SQL Server replication project

The answer by baldy below is correct, but you may also need to enable 32-bit applications in your AppPool.

Source: http://www.alexjamesbrown.com/uncategorized/could-not-load-file-or-assembly-chilkatdotnet2-or-one-of-its-dependencies-an-attempt-was-made-to-load-a-program-with-an-incorrect-format/

Whilst setting up an application to run on my local machine (running Vista 64bit) I encountered this error:

Could not load file or assembly ChilkatDotNet2 or one of its dependencies. An attempt was made to load a program with an incorrect format.

Obviously, the application uses ChilKat components, but it would seem that the version we are using, is only the 32bit version.

To resolve this error, I set my app pool in IIS to allow 32bit applications. Open up IIS Manager, right click on the app pool, and select Advanced Settings (See below)

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Then set "Enable 32-bit Applications" to True.

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All done!

.net – Resolving MSB3247 – Found conflicts between different versions of the same dependent assembly

Change the "MSBuild project build output verbosity" to "Detailed" or above. To do this, follow these steps:

Bring up the Options dialog (Tools -> Options...).
In the left-hand tree, select the Projects and Solutions node, and then select Build and Run.
- Note: if this node doesn't show up, make sure that the checkbox at the bottom of the dialog Show all settings is checked.
In the tools/options page that appears, set the MSBuild project build output verbosity level to the appropriate setting depending on your version:
- Diagnostics when on VS2012, VS2013 or VS2015 (the message in these versions says you should use "Detailed", but this is plain wrong, you should use "Diagnostics")
- Detailed when you're on VS2010
- Normal will suffice in VS2008 or older.
Build the project and look in the output window.

Check out the MSBuild messages. The ResolveAssemblyReferences task, which is the task from which MSB3247 originates, should help you debug this particular issue.

My specific case was an incorrect reference to SqlServerCe. See below. I had two projects referencing two different versions of SqlServerCe. I went to the project with the older version, removed the reference, then added the correct reference.

Target ResolveAssemblyReferences:
    Consider app.config remapping of assembly "System.Data.SqlServerCe, ..." 
        from Version "3.5.1.0" [H:\...\Debug\System.Data.SqlServerCe.dll] 
        to Version "9.0.242.0" [C:\Program Files\Microsoft Visual Studio 8\Common7\IDE\PublicAssemblies\System.Data.SqlServerCe.dll]
        to solve conflict and get rid of warning.
    C:\WINDOWS\Microsoft.NET\Framework\v3.5\Microsoft.Common.targets : 
        warning MSB3247: Found conflicts between different versions of the same dependent assembly.

You do not have to open each assembly to determine the versions of referenced assemblies.

You can check the Properties of each Reference.
Open the project properties and check the versions of the References section.
Open the projects with a Text Editor.
Use .Net Reflector.

Best Answer

Related Solutions

C# – I get a “An attempt was made to load a program with an incorrect format” error on a SQL Server replication project

.net – Resolving MSB3247 – Found conflicts between different versions of the same dependent assembly

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