Volare files cannot be demosaiced because they are not mosaic files (no bayer filters, just pure 16-bit, 6MP per channel...they are 16-bit tiffs with some added tags, previews and ICC input profile
Hence why I suggested to change the extension and to set ACR to open TIFF files. If the profile editor requires mosaic (DNG or whatever) to work then that is the problem right there
I see, thanks for that extra info.
I just don't get what changing the extension to TIFF would do as ACR can process the HDRs as is. It just can't convert them to a format Profile Editor can work with.
FWIW, I did try changing the extension but it made no discernible difference with respect to the DNG issue.