Could not load file or assembly 'System.Web.Http 4.0.0 after update from 2012 to 2013

Question

I did the upgrade according to. http://www.asp.net/mvc/tutorials/mvc-5/how-to-upgrade-an-aspnet-mvc-4-and-web-api-project-to-aspnet-mvc-5-and-web-api-2

I get the er

Answer 1

Change the Specfic version flag from true to false for the dll in the reference

Answer 2

I had this from a WCF service. For me (as the issue was displaying in local dev), I simply had to delete the contents of the bin folder under the solution. The the rebuild work fine once again.

Answer 3

The proper solution to resolve this issue is by following the steps

. Update Visual studio if you have older version to 15.5.4 (Optional)

2. Remove all binding redirects from web.config

3. Add this to the csproj file:

 <PropertyGroup>
  <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
  <GenerateBindingRedirectsOutputType>true</GenerateBindingRedirectsOutputType>
</PropertyGroup>

4. Build.

5. In the bin folder, there should be a (WebAppName).dll.config file.

6. It should have redirects in it. Copy these to the web.config

7. Remove the above snipped from the csproj file again

8. It should work

Detailed Blog

Answer 4

For me it was only crashing with this error on a production environment, not on local machine; what solved it was to delete the content of /bin folder and then to regenerate it again.

Answer 5

In my case, I was actually missing my web.config altogether, which had the appropriate binding redirects. Restoring the web.config resolved the error.

Answer 6

Me did not nothing, just copied development Bin folder DLLs to online deployed Bin folder and it worked fine for me.