I'm getting the same error on an upgrade from 4.11.8 to 6.1.2.

I was able to resolve the error by comparing the DLLs in the my site's bin directory with the one in the upgrade installation files and removing any that did not exist in the installation files.  I found some information that this error may be related to referencing both MVC 3.0 and MVC 4.0 because MVC 3.0 may be referenced in some of the old DLLs I had floating around in my bin directory.

Hi

If it is an MVC version issue. Try adding the config below to your web.config file in the '<runtime>' section

 <dependentAssembly>

        <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />

        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="4.0.0.0" />

       </dependentAssembly>

I just upgraded a 4.11.8 site to 6.1.3 and now I am getting the exact same error. The site has a few comunity packages installed such as ucomponents and crop-up, so i guess it could be a package problem.

I also tried adding, but with no effekt:

<dependentAssembly> <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" /> <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="4.0.0.0" /> </dependentAssembly> codexml Unfortunatly I am not expert on C# so i have no idea where to look for the error. Does any one have any suggestions.

As always any help will be greatly appreciated.

/Thor

Thank you

For me has worked!

Alessio

Farhad's solution worked for me. Thanks!

Turned out it was a custom dll that was my problem for me.

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