.net - Could not load file or assembly ... or one of its dependencies. An attempt was made to load a program with an incorrect format (.resx file)

Question

I am getting the following error message when compiling or attempting to run my application on Windows 7 64 bit. I've scoured the Internet and many people have the same error message. However, none of the solutions address my problem or situation. I am using Visual Studio 2010.

Error message

Error 38 Could not load file or assembly 'file:///D:/Projects/Windows Projects/Weld/Components/FileAttachments/FileAttachments/FileAttachments/bin/x86/Debug/FileAttaching.dll' or one of its dependencies. An attempt was made to load a program with an incorrect format. Line 1212, position 5. D:ProjectsWindows ProjectsWeldWeldWeld.UIfrmMain.resx 1212 5 Weld.UI

Description

OK, so I have two projects, a UI project and a FileAttachment project. The UI project has a reference to the FileAttachment project. When I compile the UI project in "Any CPU" mode, everything works fine, and it runs. I assume 'Any CPU' will run in 64-bit mode when I compile as that is the platform I am using.

I want to run/compile as x86, so I try to do that. I change the configuration for all projects to x86 and verify that these configurations are compiling to x86. I compile and get the error as stated above.

I find it odd that it compiles and works fine in 64-bit but not 32-bit. However, when compiled and deployed to users as 'Any CPU', if these users have x86 it still works for them without any problems. I just can't compile or run as x86 on my PC. Again, I can compile as Any CPU and deploy to a 32-bit PC without any problems.

Neither projects are referencing any 64-bit-only DLL files. Both projects are verified to be targeting 32-bit DLL files and .NET Framework assemblies.

I need to compile and run this locally under 32-bit mode. I need JIT edit/continue, among other things.

Here is the line of code in the resx file that is causing the problem:

 <data name="ImageList1.ImageStream" mimetype="application/x-microsoft.net.object.binary.base64">
....{mime data}....
 </data>

The resx file is verified to be generated for .NET 2.0 and is only referencing .NET 2.0 assemblies and not .NET 4.0 versions.

How can I fix this problem? I've searched the Internet and have found hundreds of people with the same error message, but a different problem.

Answer 1

This appears to be a VS 2010 bug with image lists. See https://connect.microsoft.com/VisualStudio/feedback/details/532584/error-when-compiling-resx-file-seems-related-to-beta2-bug-5252020?wa=wsignin1.0

I was able to utilize the workaround listed to get it to work for me.

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Posted by Luis Mack on 5/12/2010 at 8:50 AM I've found the same problem, only for a specific project when compiling on a 64-bit machine. A fix that SEEMS to work is to manually alter one character in the image stream EVERY TIME the usercontrol or form is edited in the designer

???? ???? AAEAAAD/////AQAAAAAAAAAMAgAAAFdTeXN0ZW0uV2luZG93cy5Gb3JtcywgVmVyc2lvbj00LjAuMC4w

Change to ???? AAEAAAD/////AQAAAAAAAAAMAgAAAFdTeXN0ZW0uV2luZG93cy5Gb3JtcywgVmVyc2lvbj0yLjAuMC4w

That is 00LjAuMC4w back to 0yLjAuMC4w at the end of the line (00 back to 0y)

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Jim