Lightroom Mobile 4.2.1 (iOS) won't open Canon EOS RP CR3 RAW

[#1]

I've had my RP for about a month, so I was pleased to see the updates released yesterday for both desktop and mobile. My desktop apps are working fine with my RP raw files. I can sync my RP CR3 raw files from my desktop to LR mobile with no problems. But if I import a RP CR3 raw file to my camera roll, using the Apple camera or SD card adapters, LR mobile won't open the raw file. The files display on the LR Mobile Import screen as black boxes with "Raw" in black letters with a white background in the center of the black box. If I select one of the files, I get an error message "Cannot load image". I am using an iPhone XS with iOS 12.2.

Is there a fix for this?

[#2]

Here is some additional info:

The "Cannot load image" error occurs when the camera is shooting Raw only. If I change the camera settings to shoot Raw+JPEG and use the Apple adaptor to transfer the files to the iOS Camera Roll, then I can import the images into Lightroom. However, when the mobile app syncs to the Cloud, only the Raw files are uploaded, not the JPEGs.

So for now I am continuing to shoot Raw+JPEG as a workaround, but the behavior sure seems weird.

Am I doing something wrong, or is this a bug? I'm also wondering if the problem is caused by the lack of support for Canon EOS RP Raw files in iOS?

[#3 · Accepted solution]

I solved the problem.

The message "Cannot load image" means that LR Mobile can not render a preview of the raw image to be imported. I'm guessing this is because it uses iOS to render the preview, and iOS does not yet support EOS RP raw images. However, if you ignore the error message, and go ahead and tap the check mark on the upper right corner of the screen, LR Mobile goes ahead and correctly imports the raw image. Once imported, it generates its own preview correctly.

I hope this helps someone else with a similar problem.