How to Fix, Could not load file or assembly 'XXX' or one of its dependencies. Strong name signature could not be verified

It seems that you are trying to debug the ASP.NET MVC source code and have built your own version of the System.Web.Mvc assembly. The problem with this approach is that you cannot sign it with the official keys. This means that any third party component that you might be using and which depends on System.Web.Mvc should also be recompiled against your own version. Take for example Razor. It also depends on System.Web.Mvc. Did you recompile that as well?

Personally I find it extremely difficult to be building your own version of System.Web.Mvc. In practice I debug the source code by using the publicly available PDB symbols. So I would advice you NOT to be compiling your own version but work with the official one. Take a look at this post: https://stackoverflow.com/a/13610108/29407

Just resolved the same problem:

• build solution with asp.net source code (mine is called 'Runtime.sln')
• unload tests folder from it
• open properties of System.Web.Mvc project
• uncheck Sign on Signing tab
• try to rebuild solution
• uncheck Sign on Signing tab for each failed project

I also removed strong name details from InternalsVisibleTo attributes in AssemblyInfo.cs but it might needed only if you want to build test projects as well.

After that I added System.Web.Mvc, System.Web.WebPages.Deployment and System.Web.WebPages projects as existing projects to my new solution and now I can debug their source code.

I've had this before and removing the reference to System.Web.Mvc and re-adding it worked.

I also did a clean and re-build which worked.

Hope that helps