Why MacOS Sierra can't support RAW files taken by Canon EOS R

Apple only updates its Camera RAW database for the newest macOS which at the moment is macOS Big Sur.

Apple do not support the Camera RAW database in its older macOS's so no you will never be able to open your

new Canon cameras raw files using the macOS High Sierra, Finder, Quicklook, Preview or Photos.

Download and install Adobes DNG Converter software, it is free, this converts your raw files to the DNG format

and your mac will see them.

https://helpx.adobe.com/photoshop/using/adobe-dng-converter.html

No, and extremely unlikely they will.

RAW compatibility update is traditionally provided separately from OS updates, so it is still a possibility. However, the fact that R (and M50) use an entirely new file format, instead of just changing the metadata within an existing file format, may complicate matters. I would suggest moving to Lightroom or another third party decoder.

https://www.dpreview.com/forums/thread/4359782

Van Tri wrote:

the only way to open the raw files in Mac is to wait and hopefully Apple will add it in.

As explained, support for the EOS R will not be added to High Sierra. It is supported with Mojave 10.14 and later.

I told you Apple will not add it on on older macOS's like High Sierra.

If the update their camera raw database it will on be available if you are running Big Sur.