Prevent runtime assembly binding to older assemblies

Question

I have a solution with 3 projects:

Solution.Web.Core - Common classes
Solution.Web.Mvc - MVC 4
Solution.Web.Api - Web Api 2 aka running ASP.NET 5.0 (beta-1) assemblies

I have the WebApi set up as a child application (in IIS) of the MVC application, however, I'm having trouble achieving full isolation of this project.

Because Solution.Web.Core has some references to ASP.NET 4.0 assemblies, if I add a reference to this project in Solution.Web.Api I get the following exception at runtime:

Could not load file or assembly 'System.Net.Http.Formatting, Version=5.0.0.0, 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)

How can I prevent this error occurring in Solution.Web.Api so that I can reference Solution.Web.Core despite it referencing older assembly versions of ASP.NET?

Note: Since the error says "System.Net.Http.Formatting or one of its dependencies" I'm honestly not even sure how to find out which is the exact offending assembly(s).

Youmight look at this: http://msdn.microsoft.com/en-us/library/w4atty68.aspx — Mike Cheel, Jul 13 '13 at 18:32
Thanks. This seems to be for the .NET runtime. All 3 of my applications are running .NET 4.5. It is the ASP.NET assemblies that differ. — parliament, Jul 13 '13 at 19:27
I think though there is some setting (I was thinking that was it) that allows you to specify what you are asking. — Mike Cheel, Jul 14 '13 at 05:43

Ankan Mookherjee · Accepted Answer · 2015-03-03T10:01:07.307

Change the Web.Config of the View section from

<system.web.webPages.razor>
<host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, **Version=5.0.0.0**, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<pages pageBaseType="System.Web.Mvc.WebViewPage">
  <namespaces>

to

<system.web.webPages.razor>
<host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, **Version=5.2.3.0**, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<pages pageBaseType="System.Web.Mvc.WebViewPage">
  <namespaces>

score 1 · Answer 2 · answered Jul 14 '13 at 18:23

I got past this issue by just starting over with MVC 5 + Web Api 2.

However, just found this blog post answer which seems like it probably would've worked for me:

To allow an MVC 4 project to play nice with 5.0 beta assemblies (at least the CORS assemblies in the blog post) change web config to the following:

<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1" xmlns:bcl="urn:schemas-microsoft-com:bcl">
  <dependentAssembly>
    <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
    <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
  </dependentAssembly>
  <dependentAssembly>
    <assemblyIdentity name="System.Web.WebPages.Razor" publicKeyToken="31bf3856ad364e35" />
    <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
  </dependentAssembly>
  <dependentAssembly>
    <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
    <bindingRedirect oldVersion="1.0.0.0-5.0.0.0" newVersion="5.0.0.0" />
  </dependentAssembly>
  <dependentAssembly>
    <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
    <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
  </dependentAssembly>
  <dependentAssembly>
    <assemblyIdentity name="EntityFramework" publicKeyToken="b77a5c561934e089" />
    <bindingRedirect oldVersion="0.0.0.0-5.0.0.0" newVersion="5.0.0.0" />
  </dependentAssembly>
  <dependentAssembly>
    <assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35" />
    <bindingRedirect oldVersion="1.0.0.0-1.3.0.0" newVersion="1.3.0.0" />
  </dependentAssembly>

Prevent runtime assembly binding to older assemblies

2 Answers2