I am trying to use windbg to research a hang dump file created on an x64 machine for our x86 process. This is a 4.0 x86 application, so just to get an unmanaged stack, I had to
As others have said already, this can be caused by a 64 bit application (like the default Task Manager, for example) creating a dump file of a 32 bit process.
I was able to resolve the problem using the soswow64 WinDbg extension from poizan42 on GitHub. I've found it through this blog entry, which also provides some more detailed information about the issue.