Question

I’ve got a C# 2.0 project which is set to target ‘Any Cpu’, however it is referencing a C++ project that’s building a 32 bit dll.

When I try to run my program on a 64bit machine I get the following error:

System.BadImageFormatException was
unhandled Message: Could not load file
or assembly TreeTMHook,
Version=1.0.2889.19619,
Culture=neutral, PublicKeyToken=null
or one of its dependencies. An attempt
was made to load a program with an
incorrect format.

How can I fix this?

Update

I want to be able to keep the main project as any cpu.

Thanks.

Answer 1

You’ll need to build your .NET project as 32bit (x86 target) if you want it to correctly load a 32-bit DLL on a 64bit machine.

RE: Update:

If you want to keep your project as “Any CPU”, you’ll need a 32bit and a 64bit version of the DLL, and make sure the appropriate version is distributed with your app. If you can’t build the other project as 64bit, you must build your .NET project as 32-bit only.