The Zoom MS Decoder plug-in is only recognized by the 32 bit version of Wavelab. For that reason I am also running both the 32 bit and 64 bit versions of Wavelab, depending on which plug-ins I plan on using. I agree the Zoom H2n is a great product. However, I have not figured out how to contact Zoom for customer support to request a 64 bit version of the plug-in.