Hey! 
I recently ran into a problem regarding the Audio-Mixdown export-function in Nuendo:
I had recorded a few impulse responses of rooms in our faculty in Nuendo, and wanted to import the cut IR´s into REW to demonstrate Waterfall Diagrams. When i tried to import the Files, which i exported as 48kHz/24Bit .wav, i got the following error message:
Looks like REW recognizes the Wave-File Container and .wav file-ending, but the data inside the File is read as MP3?
Is there something i am missing, or some Export Setting i overlooked? I never ran into this kind of problem before, so i sadly have no clue of what the problem could stem from.
Maybe this just is a quirk of Mixdown and File creation out of Cubase/Nuendo? It shouldn´t be problem based in REW, as i also tried the same process with Pro Tools, and it worked like a charm
Thanks in advance for any answers that may shine light on the issue! 