Could not load file or assembly System, Version=2.0.5.0 in .NET 4 MVC 4 application

Question

Been searching for ages, can't find anything helpful. Here is the exception I'm getting:

Could not load file or assembly 'System, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e, Retargetable=Yes' or one of its dependencies. The given assembly name or codebase was invalid. (Exception from HRESULT: 0x80131047)   Exception Details: System.IO.FileLoadException: Could not load file or assembly 'System, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e, Retargetable=Yes' or one of its dependencies. The given assembly name or codebase was invalid. (Exception from HRESULT: 0x80131047)  Stack Trace:   [FileLoadException: Could not load file or assembly 'System, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e, Retargetable=Yes' or one of its dependencies. The given assembly name or codebase was invalid. (Exception from HRESULT: 0x80131047)] StructureMap.Graph.PluginGraph..ctor() in c:\BuildAgent\work\996e173a8ceccdca\src\StructureMap\Graph\PluginGraph.cs:41 StructureMap.PluginGraphBuilder..ctor() in c:\BuildAgent\work\996e173a8ceccdca\src\StructureMap\PluginGraphBuilder.cs:22 StructureMap.InitializationExpression..ctor() in c:\BuildAgent\work\996e173a8ceccdca\src\StructureMap\InitializationExpression.cs:22 StructureMap.ObjectFactory.Initialize(Action`1 action) in c:\BuildAgent\work\996e173a8ceccdca\src\StructureMap\ObjectFactory.cs:47 ... 

This applications works fine on the test server but is throwing this exception on the production server. As you can see, the StructureMap code is what is causing the exception.

I had to convert this app to .NET 4 from 4.5 because 4.5 wasn't installed on the production server. After the conversion, the app still works fine on my local machine and the test server.

I have already set the Copy Local to True for the System assembly, but since the referenced version is 4.0.0.0 and not 2.0.5.0, I this made no difference.

Let me know if any more info is needed. Any help you may be able to provide is appreciated.

Answer 1

Make sure your .NET framework is patched. Microsoft released patches to .NET to allow Portable Class Libraries to properly find the appropriate runtime (KB2468871). If you are seeing the above exception (or something like it), it means you're missing the latest .NET framework patches.