c# globalconfiguration - Could not load file or assembly System.Net.Http, Version= with ASP.NET (MVC 4) Web API OData Prerelease

7 Answers

Visual Studio 2013 has a new feature to take care of this. When you build the app, you should see warnings about different versions of an assembly being referenced. Double click the warning to add assembly binding redirects to the web.config.

See for more details.

jeff.eynon notes below that you need to have the web.config checked out (if using TFS source control) to get VS to edit the file automatically. Thanks for the tip!

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After installing the Microsoft ASP.NET Web API OData package 5.0.0-rc1 prerelease I end up with the following exception:

Could not load file or assembly 'System.Web.Http, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

My MVC 4 project is brand new and really small, nothing fancy in it. I target .NET framework 4.5

I need this nuget package to implement PATCH using the Delta class (When I use the version of the package, the Delta class is not working).

How can I fix that?

My versions of System.Web.Http

In GAC I have version of System.Web.Http

gacutil -l System.Web.Http The Global Assembly Cache contains the following assemblies: System.Web.Http, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL

In Visual Studio, when I browse assemblies, the given version of System.Web.Http is (Why?)

In my project, the reference to System.Web.Http

  • Has the version
  • Points to the \lib\net45\ folder of the package
  • Has CopyLocal=true

Things I tried

I tried to bind redirect v to in Web.config

    <assemblyIdentity name="System.Web.Http" publicKeyToken="31bf3856ad364e35" culture="neutral" />
    <bindingRedirect oldVersion="" newVersion="" />

But it gives me another exception:

Attempt by method 'System.Web.Http.GlobalConfiguration..cctor()' to access field 'System.Web.Http.GlobalConfiguration.CS$<>9__CachedAnonymousMethodDelegate2' failed.

I guess that v really need to be used by core Web Api engine.

Linked questions

Code Analysis error Could not load file or assembly 'System.Net.Http, Version= in MVC4 Web API Could not load file or assembly 'System.Net.Http, Version= in MVC4 Web API

I met the same problem and I resolved it by setting CopyLocal to true for the following libs:


I must to add that I use MVC4 and NET 4

Or you could do this from NuGet Package Manager Console

 Install-Package Microsoft.AspNet.WebApi -Version 5.0.0

And then you will be able to add the reference to System.Web.Http.WebHost 5.0

This error popped up several times on several different projects.

What I finally figured out is that when I would build, there was already a copy of the system.web.mvc binary assembly in my bin folder.

To fix this, right-click on the assembly in the list of references and select "properties". Check to see if this is the latest version by looking at the "Version" property. If it is, switch "Copy Local" to true.

This will make sure that the version referenced in your project is the version that will end up in your binaries folder.

If you still get the error, try running nuGet to get the latest version, then try the aforementioned again.

Good luck - this error is a pain!

i solve by way nuget. the first you install nuget. the second you use.
illustration follow:

third : Check to see if this is the latest version by looking at the "Version" property.

The finaly : you check project have latest version again.

After modifying the References in the Web.config file as mentioned above, we resolved the references.

I was facing similar issue.

For us we have reference Microsoft.Data.Edm.dll and OData.dll and other assemblies from Program Files:

C:\Program Files (x86)\Microsoft WCF Data Services\5.0


C:\Program Files (x86)\Microsoft WCF Data Services\5.0

and version was 5.6.4.

Once I change the reference of both assemblies to C:\....Project\packages\Microsoft.Data.Edm.5.6.0 , the issue was resolved

If this issue occurs, kindly check web.config in below section

Below section gives the version of particular dll used

after checking this section in web.config, open solution explorer and select reference from the project tree as shown . Solution Explorer->Reference

After expanding reference, find the dll which caused the error. Right click on the dll reference and check for version like shown in the image above.

If both config dll version and referenced dll is different you would get this exception. Make sure both are of same version which would help.