Assembly binding redirect for Unity not working

Question

I'm creating a new MVC 4 website, and I'd like to use the Unity.MVC3 library to integrate with the DependencyResolver stuff built into MVC.

I also want to reference some data-access DLLs from an older, much larger project.

My problem is that Unity.MVC3 and the older DLLs are compiled against different versions of Unity, 1.2.0.0 and 2.1.505.0, respectively. I tried creating a binding redirect in my web.config file like so:

  <dependentAssembly>
    <assemblyIdentity name="Microsoft.Practices.Unity" publicKeyToken="31bf3856ad364e35" />
    <bindingRedirect oldVersions="1.2.0.0-2.1.505.0" newVersion="2.1.505.0" />
  </dependentAssembly>

However, I still get the following error:

 Could not load file or assembly 'Microsoft.Practices.Unity, Version=1.2.0.0, 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)

I turned on assembly binding logging, and the last two lines state:

 WRN: Comparing the assembly name resulted in the mismatch: Major Version
 ERR: Failed to complete setup of assembly (hr = 0x80131040). Probing terminated.

Why isn't my binding redirect being respected? Is there a way to override its checking for major version conflicts?

Can you see in the fusion log whether the binding redirect is actually being used? — fsimonazzi, Sep 15 '12 at 01:42

score 2 · Answer 1 · edited May 23 '17 at 12:23

There is a typo in the key token:

<assemblyIdentity name="Microsoft.Practices.Unity" 
     publicKeyToken="31bf856ad364e35" />

should be:

<assemblyIdentity name="Microsoft.Practices.Unity" 
     publicKeyToken="31bf3856ad364e35" />

Binding redirect does not complain in case of typos, it just does nothing.

I've made a test application, with this configuration it works:

<runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Practices.Unity" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.2.0.0" newVersion="2.1.505.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>

Pay attention to xmlns, without it, it fails silently.

Good catch! Doesn't seem to have solved the problem, though. Still getting the error. — Brian Sullivan, Sep 10 '12 at 16:31

Assembly binding redirect for Unity not working

1 Answers1