effect on dlls when moving to 64 bit machine

Question

We've had a 32 bit terminal services computer running some Windows services we constructed using .NET. Recently we moved everything to a 64 bit machine. Most things work. However, we are getting grief from a dll for apachefop.net.

In particular we get the following error

Error: Plugin Transcript Service Execution Failed: Could not load file or assembly 'apachefop.net, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. An attempt was made to load a program with an incorrect format.

I'm guessing that this is because it isn't meant to work on a 64 bit machine. Any suggestions about how to rectify this type of situation?

Answer 1

The problems seems to be caused by the fact that your assembly has been compiled with the anycpu setting. In this mode, when run on a 64 bits machine, your process automatically becomes a 64 bits process while your native references don't... And as it is not possible to load 32bits libraries from a 64 bits process you're running into troubles.

To quickly diagnose if it is the case you can use the corflags.exe which is part of the .net framework : corflags.exe pathtoyourdotnetprogram /32bit+

Then run your program. If your soft is running well, then you should change the anycpu settings in your project to force the compiler to compile to a 32bits assembly.