Assembly.getType is not working

Question

We have a ddex assembly (foo.dll) which we use to make a connection to db2. When we try to load the assembly using reflection within our package, it works fine. But when we do a assembly.getType to get a class(c1) in that assembly, it fails with an error message "Could not load file or assembly
foo, Version=9.1.0.0, Culture=neutral,
PublicKeyToken=7c307b91aa13d208' or one of its dependencies. The system
can not find the file specified."
This seems to work with VS2005 without any problems
This works when we load the foo outside the package and the assembly.getType works just fine. Also one other thing that we noticed is that when we create a windows aplication and change the target framework type of that application to framework 4.0 without doing anything else the assembly.GetType works just fine.
Can someone please help us with this issue.

Answer 1

It probably means that the assembly you are loading fails to pull some other assembly when it needs it. To have more details you can run fuslogvw to see the detailed protocol of assembly load/bind process

Answer 2

We already checked the fusion log. It doesn't seem to indicate any failure

 

*** Assembly Binder Log Entry  (10/21/2009 @ 3:14:29 PM) ***

The operation was successful.
Bind result: hr = 0x0. The operation completed successfully.

Assembly manager loaded from:  C:\WINDOWS\Microsoft.NET\Framework\v4.0.21006\clr.dll
Running under executable  C:\Program Files\Microsoft Visual Studio 10.0\Common7\IDE\devenv.exe
--- A detailed error log follows.

=== Pre-bind state information ===
LOG: User = ur1
LOG: Where-ref bind. Location = foo.dll
LOG: Appbase = file:///C:/Program Files/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 LoadFrom load context.
WRN: Native image will not be probed in LoadFrom context. Native image will only be probed in default load context, like with Assembly.Load().
LOG: Using application configuration file: C:\Program Files\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\v4.0.21006\config\machine.config.
LOG: Attempting download of new URL file:///foo.dll.
LOG: Assembly download was successful. Attempting setup of file: foo.dll
LOG: Entering run-from-source setup phase.
LOG: Assembly Name is: foo, Version=9.1.0.0, Culture=neutral, PublicKeyToken=null
LOG: Re-apply policy for where-ref bind.
LOG: Where-ref bind Codebase does not match what is found in default context. Keep the result in LoadFrom context.
LOG: Binding succeeds. Returns assembly from foo.dll.
LOG: Assembly is loaded in LoadFrom load context.
WRN: The same assembly was loaded into multiple contexts of an application domain:
WRN: Context: LoadFrom | Domain ID: 1 | Assembly Name: foo, Version=9.1.0.0, Culture=neutral, PublicKeyToken=null
WRN: Context: Neither | Domain ID: 1 | Assembly Name: foo, Version=9.1.0.0, Culture=neutral, PublicKeyToken=null
WRN: This might lead to runtime failures.
WRN: It is recommended to inspect your application on whether this is intentional or not.
WRN: See whitepaper http://go.microsoft.com/fwlink/?LinkId=109270 for more information and common solutions to this issue.

 

Answer 3

This is not necessarily the foo assembly. Do you see any failures in the fusion log? If foo references some other assembly the attempt to load it can be deferred to the moment when the type using it is first requested. Loading your assembly into LoadFrom can cause this sort of problems because it changes the binding behavior. And the fact that foo is loaded twice looks especially suspicios

Answer 4

We cannot figure out why it gets loaded twice in VS 2010. When we use VS2005, the fusion log appears to be loading only into LoadFrom.

For all the assemblies that foo references, the fusion log shows a file not found exception.

*** Assembly Binder Log Entry  (10/21/2009 @ 3:14:11 PM) ***

The operation was successful.
Bind result: hr = 0x0. The operation completed successfully.

Assembly manager loaded from:  C:\WINDOWS\Microsoft.NET\Framework\v4.0.21006\clr.dll
Running under executable  C:\Program Files\Microsoft Visual Studio 10.0\Common7\IDE\devenv.exe
--- A detailed error log follows.

LOG: IJW explicit bind. File path:fooreferenced.dll
LOG: IJW assembly bind returned file not found.

 

Answer 5

Is it possible for you to provide some steps on how to reproduce this scenario? This will help us in narrowing down what's the root cause here.

--
Regards,
Saurabh

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http://blogs.msdn.com/saurabhjain