To begin, yes I have updated Lightroom, yes I have updated and installed Canon RAW!
Here is my issue, I just got a new Canon 1DX Mark II and shot a couple of test shots and attempted to upload them to my Lightroom CC. I am using a Sandisk CFast card with its reader. When I load the card it appears on my desktop, it does not load into Lightroom. Once I open LR I can see the drive and the images under folder as the EOS Digital and the DCIM folder contains my images. However, it did not create a 2017 Folder where all of my images are housed. I can edit the images as long as the drive is installed yet the moment I remove the card from the reader I get a question mark on the drive an unable to access the RAW images.
About to go on a sizable shoot in a week and need some help resolving this issue. I just converted to LR from Aperture within a year, therefore it may be a basic issue that I am unaware of yet need some support.
Sounds like your original import did an "add" instead of a "copy" (center top of the import dialog), thus leaving the images on the memory card. LR is not supposed to allow that, but sometimes it happens.
If this is the case, you need to copy the images off the card to your hard drive using the OS file browser (Finder or Explorer), then point LR to the new location.