Assembly Binding Error: Bind result: hr = 0x80070002. The system cannot find the file specified

Question

I have a Visual Studio 2010 solution that contains a class library (ProjectA) and two Sharepoint projects (ProjectB & ProjectC). The dependency order is ProjectB references ProejctA and ProjectC references both ProjectA & ProjectB.

On one particular development machine i get the following error when trying to build ProjectC:

Compilation failed. Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.

When looking into the fusion log i noted the following error:

* Assembly Binder Log Entry (14/06/2012 @ 09:38:32) *

The operation failed.

Bind result: hr = 0x80070002. The system cannot find the file specified.

Assembly manager loaded from: C:\Windows\Microsoft.NET\Framework\v4.0.30319\clr.dll

Running under executable C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\devenv.exe

--- A detailed error log follows.

=== Pre-bind state information === LOG: User = DOMAIN\username

LOG: DisplayName = ProjectB, Version=0.0.0.0, Culture=neutral, PublicKeyToken=aaaaaaaaaaaaaaaa, processorArchitecture=MSIL (Fully-specified)

LOG: Appbase = file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/

LOG: Initial PrivatePath = NULL

LOG: Dynamic Base = NULL

LOG: Cache Base = NULL

LOG: AppName = devenv.exe

Calling assembly : (Unknown).

LOG: This bind starts in default load context.

LOG: Using application configuration file: C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\devenv.exe.Config

LOG: Using host configuration file:

LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config.

LOG: Post-policy reference: ProjectB, Version=0.0.0.0, Culture=neutral, PublicKeyToken=aaaaaaaaaaaaaaaa, processorArchitecture=MSIL

LOG: GAC Lookup was unsuccessful.

LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/ProjectB/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PublicAssemblies/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PublicAssemblies/ProjectB/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PrivateAssemblies/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PrivateAssemblies/ProjectB/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/CommonExtensions/Microsoft/TemplateProviders/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/CommonExtensions/Microsoft/TemplateProviders/ProjectB/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PrivateAssemblies/DataCollectors/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PrivateAssemblies/DataCollectors/ProjectB/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PrivateAssemblies/DataCollectors/x86/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PrivateAssemblies/DataCollectors/x86/ProjectB/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/CommonExtensions/Microsoft/Editor/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/CommonExtensions/Microsoft/Editor/ProjectB/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/CommonExtensions/Platform/Debugger/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/CommonExtensions/Platform/Debugger/ProjectB/ProjectB.DLL. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/ProjectB/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PublicAssemblies/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PublicAssemblies/ProjectB/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PrivateAssemblies/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PrivateAssemblies/ProjectB/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/CommonExtensions/Microsoft/TemplateProviders/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/CommonExtensions/Microsoft/TemplateProviders/ProjectB/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PrivateAssemblies/DataCollectors/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PrivateAssemblies/DataCollectors/ProjectB/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PrivateAssemblies/DataCollectors/x86/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/PrivateAssemblies/DataCollectors/x86/ProjectB/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/CommonExtensions/Microsoft/Editor/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/CommonExtensions/Microsoft/Editor/ProjectB/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/CommonExtensions/Platform/Debugger/ProjectB.EXE. LOG: Attempting download of new URL file:///C:/Program Files (x86)/Microsoft Visual Studio 10.0/Common7/IDE/CommonExtensions/Platform/Debugger/ProjectB/ProjectB.EXE. LOG: All probing URLs attempted and failed.

I have tried:

1. Removing the reference to ProjectB and re-adding it both:
   • a) as a project reference
   • b) as a manual reference directly to the debug folder of projectB
2. Manually placing the ProjectB.dll into the GAC
3. Changing the "Copy Local" option from True to False (and back to True)

And only (2) placing the assembly in the GAC allows ProjectC to build. Why is it not finding the assembly as it should (and does on other machines)?

Answer 1

So it turns out the reason the assembly could not be found was because we are Delayed Signing the Assemblies this means that:

Because the assembly does not have a valid strong name signature, the verification of that signature must be turned off. You can do this by using the –Vr option with the Strong Name tool.

I had already done this for all required public keys however ONLY in the x64 Visual Studio command prompt. I also needed to add the verification skipping for x86 in the x86 version of the Visual Studio Command Prompt.

I only managed to find this because trying a specific command based build/deployment script i noted the following exception with one of the test assemblies:

Could not load file or assembly 'ProjectC.Tests, Version=0.0.0.0, Culture=neutral, PublicKeyToken=e72f8d3506b83180' or one of its dependencies. Strong name validation failed. (Exception from HRESULT: 0x8013141A)

Answer 2

PublicKeyToken=aaaaaaaaaaaaaaaa can be different or might be the version number of assembly is different. I think you should use Fusion Log Viewer to Debug as described and hope fully you will solve your problem.