I have compiled a .NET application using Any CPU option. This .NET application uses an unmanaged dll (managed wrapper) that encapsulated C++ calls. This .NET wrapper resides in GAC.
When I run the .NET application it runs fine on XP 32 bit. But when I run it on XP 64 bit, it fails and gives the following exception:
Could not load file or assembly "Dll name, version, Culture=neutral, PublicKeyToken" or one of its dependencies.
How do I resolve this?
You need to use the x86 CPU option. If you know that one of your unmanaged dependencies is 32bit then you need to build your solution with the x86 option for the CPU. This ensures that even on a 64bit operating system your application will be run in a 32 bit process.
This is required because its not possible to load 32 bit compiled code into a 64 bit process.
You need to make sure your unmanaged dll is also 64bit capable and within the search path.
You can find some explanation on Microsoft Connect website
Related
I have an 64-bit application that uses a .NET DLL, and is returning an error from CoCreateInstance() saying "class not registered". (0x80040154)
Now, this has been running fine as a 32-bit application for a long time, and has no problem calling the .NET DLL, which gets registered as part of the installation, or on my development machine, gets registered as part of the build process. The recent conversion to 64-bit application has started causing this error (the rest of the application is now running fine as 64-bit, so no other issues there).
The application is non-managed C++. The DLL is managed C#, .NET 2.0, and is set to "Any CPU". Both are built in VS2010. My install package uses Regasm to register the DLL, and I wondered if maybe I needed a 64-bit version of regasm, however, I believe I am already using that. Visual Studio is also set up to register the DLL as part of the build process, but even running the 64-bit program in the debugger still cannot find the class.
What do I need to do to register the DLL so that the 64-bit version of the program can find the DLL through CoCreateInstance()?
Probably your installer uses 32 bit regasm from:
C:\Windows\Microsoft.NET\Framework\v4.0.30319\RegAsm.exe
But it should use 64 bit regasm:
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\RegAsm.exe
I have a .NET application that calls a C++ API using P/Invoke. The C++ dll has a dependency from a third-party dll. That third party dll calls LoadLibrary to dynamically load libeay32.dll, an OpenSSL dependency.
After doing several tests I found out that the .NET application works correctly in Windows 10 but fails in some deployments using Windows 7. The cause of the failure is because the .NET process is not loading libeay32.dll. I tried placing libeay32.dll in the same directory as the process and in the System folder (having in mind the Dynamically load search order) but the failure persisted in Windows 7 32 bits only. Furthermore, if I called the API dll from a C++ console application it worked without issues in all platforms. To solve the problem I called LoadLibrary in the .NET application, before making the P/Invoke calls to the C++ API, and it worked in all target platforms (Windows 10/7 32 and 64 bits).
Why would LoadLibrary fail to load libeay32.dll in Windows 7 but not Windows 10 if called from the C++ dll dependency of the API called using P/Invoke?
Edit
Some notes from comments:
All the compiled assemblies are targeted for x86 architecture.
Before posting the question, I verified that no dependencies files
where missing, using dependency walker.
Likely because the dll is depending on some files that are missing. Use dependency walker and see what files it requires. Check on both systems. The tool will show you in red the missing files. Do not blindly copy the files.See what they are, what runtime or setup is required to deploy them, and deploy them properly.
.Net applications can be built with AnyCPU as their target and run in both 64 and 32 bit modes, but if you choose AnyCPU for your target the operating system will choose one based on it's preference. What this can mean if you have native dependencies is that the library that you're depending on can't be loaded because you're running in the wrong bitness. If you can constrain the application to the bitness you're expecting it might work better.
I'm attempting to use a CAN device over USB that comes with a native DLL that needs to be wrapped by a .NET C# class (source code provided by the vendor) that gets included in one's project. Their sample applications target .NET 2.0 where my application targets .NET 4.0. I'm able to use the code in their sample apps and debug everything just fine, however, when I try to debug my application, I get a BadImageFormatException:
System.TypeInitializationException: The type initializer for 'TotalPhase.KomodoApi' threw an exception. ---> System.BadImageFormatException: An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B)
The only differences between their code and mine appears to be that their code is an application built for .NET 2.0 and (currently) my code is running as an MSTest unit test in .NET 4.0. Both solutions target AnyCPU. I'm running on a Windows 7 Ultimate 64-bit install. Even changing from AnyCPU to x86 didn't make any difference. How can I get this native DLL to load in an AnyCPU project?
If you get a BadImageFormatException when interfacing with a native DLL, it almost always means that you are trying to interface with a 32-bit DLL while running in the 64-bit CLR, or vice versa.
When you run the sample applications, do the processes have *32 in the "Image Name" column of Task Manager's "Processes" tab? That indicates the applications are running in the 32-bit CLR. Check your own application as well. It is possible that the machine you are testing on only has a 32-bit .NET 2.0 runtime, but both 32-bit and 64-bit .NET 4.0 runtimes, or the other way around.
If you are distributing a native DLL with your .NET application, then you should set your startup project to target x86 or x64 (as opposed to AnyCPU), depending on whether the native libraries are 32-bit or 64-bit. You can always ship both 32-bit and 64-bit versions, and let the installer choose which binaries to install based on the client architecture.
Alternatively, you can ship both 32-bit and 64-bit DLLs with different file names, define separate P/Invoke stubs for each version, and decide which one to call at runtime. The easiest way to do this would probably be to wrap your native calls in an interface (e.g., INativeMethods) and choose which implementation to instantiate at runtime based on IntPtr.Size. With this method, you could still target AnyCPU.
I am running a .NET 4.0 application, Access database on a Windows 7 x64 bit OS + Office 2010 (64-bit compatible provider Microsoft.ACE.OLEDB.12.0).
Platform target x86:
Provider problem:
The 'Microsoft.ACE.OLEDB.12.0' provider is not registered on the local machine
Platform target x64 or Any CPU:
DLL file problem:
System.BadImageFormatException: Could not load file or assembly 'Interop.SHDocVw, Version=1.1.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. An attempt was made to load a program with an incorrect format.
You can solve the first problem by installing the 32-bit version of the provider. Download is here.
The second problem is very strange, an interop library should contain IL only and not have a dependency on the processor architecture. When I create an interop DLL from c:\windows\system32\shdocvw.dll and run CorFlags.exe on it then I get this:
Version : v2.0.50727
CLR Header: 2.5
PE : PE32
CorFlags : 1
ILONLY : 1
32BIT : 0
Signed : 0
Note how ILONLY is on, 32BIT is off. This should run on a 64-bit machine just fine. I'm not close to one right now to check, try this yourself to compare. To get a better answer you should document which version of Internet Explorer you have installed and whether you used the 64-bit or the 32-bit version of the DLL to generate the interop. The latter is in the c:\windows\syswow64 directory.
As I've noted in the comments, this is likely due to the fact your reference DLL is 32-bit. I recently had this issue, you cannot load DLLs of varying bit-ness into a single process. To get around this, you ideally need to equalise the bit-ness of the DLLs.
If that really isn't an option, you can create a new process to house the offending DLL and marshal the calls across using IPC, this however, is less than ideal. I believe there is also a way to shim a DLL with another DLL of correct bit-ness, but likely under the hood it is marshalling cross-process calls again.
I have used IPC successfully in the past to gain access to a 32-bit DLL from a 64-bit application. Luckily for me, there wasn't anything complicated to marshal, it was basic chunky request-response semantics.
You can change the build Platform target on your project for x86 as a temporary solution.
By default, my application references a mixed mode DLL, so this DLL is both 32 and 64 bit. On a 32 bit system, my app is MSIL and loads the 32 bit DLL. On a 64 bit system, my app loads the 64 bit.
However on a 64 bit system, in an older version of the assembly that I am referencing, they only created a 32 bit version. So I fail to load this. I was looking at doing it dynamically, and ideally I would want my MSIL app in 64 bit mode to load the 32 bit DLL. Is this possible?
Also it would be nice to resolve it to a different version than what I have referenced as well.
Any help appreciated.
You cannot load 32-bit DLLs into 64-bit processes. "Any CPU" assemblies work because the JIT handles the IL compilation before execution, creating a native image of the appropriate type; CPU-specific assemblies don't support JITing to different types.
This is a Windows limitation, not a CLR limitation.