Error:Upgrade MVC4 to MVC5 in VS2012

Question

I am getting below error after upgrade my project from MVC4 to MVC5. I followed How to Upgrade an ASP.NET MVC 4 and Web API Project to ASP.NET MVC 5 and Web API 2

Assembly 'WebServices.WebApi.External, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' uses 'System.Web.Http, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' which has a higher version than referenced assembly 'System.Web.Http, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' How to solve this issue?

Answer 1

I also follow that article without full success at start but

To fix this "simple" create new web mvc project and save it then open web.config, web.config from views, packages.config, and .csproj in notepad

then open your project and look at difference in entry for version numbers of files e.g. in packages you should see

<package id="Microsoft.AspNet.Mvc" version="5.0.0" targetFramework="net45" />

but you can have

<package id="Microsoft.AspNet.Mvc" version="4.x.x.x" targetFramework="net40" />

in web.config

<dependentAssembly>
        <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
      </dependentAssembly>

but you can have

<dependentAssembly>
        <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
      </dependentAssembly>

in .csproj

<Reference Include="System.Web.Helpers, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\Microsoft.AspNet.WebPages.3.0.0\lib\net45\System.Web.Helpers.dll</HintPath>
    </Reference>

but you can have

<Reference Include="System.Web.Helpers, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <Private>True</Private>
      <HintPath>..\packages\Microsoft.AspNet.WebPages.2.0.20710.0\lib\net40\System.Web.Helpers.dll</HintPath>
    </Reference>

replace all with newer values

after that do Ctrl+Shift+B and in nuget console update all packages by comand Update-Package

for me this work finally

Answer 2

I solved this by installing the System.Web.Http.WebHost. You can install by using nuget and search for WebHost. This is the exact link https://www.nuget.org/packages/Microsoft.AspNet.WebApi.WebHost/5.1.0

you can also install it from the Package Manager Console: PM> Install-Package Microsoft.AspNet.WebApi.WebHost

Answer 3

I had a similar problem, it was due to me using the

_bin_deployableAssemblies

This folder had the System.Web.Http in it at version 4. I deleted this folder and it worked