Applications created from C# are compiled as managed code, which makes them platform independent (like Java, for example). Thus, when you compile a C# application on a 32-bit machine and then deploy it on a 64-bit machine, it will, by default, try to run as a 64-bit application. Then, it will try to find the 64-bit version of the MWArray.dll, and if it fails, the mentioned error will be shown.
To work around this issue, set the option "Properties -> Build -> Platform target" to "x86" instead of "Any CPU" before compiling your C# application. This will have the effect that the application will start in 32-bit mode on the 64-bit machine.
