Upon further inspection, changing the "extension" attribute for the IOMessage struct from [wchar_t; 12] to [wchar_t; 24] did the trick and it ran fine after that. This was done in src/shared_def.rs at lines 110, 179, and 350.
The length of the message coming from the driver just needed a larger struct to hold it. I'm unsure if this is different on different versions of Windows, but it might be worth looking into.
Thank you!