Hmm, interesting problem. I am not the MOST experienced with this issue, but I do know there is a photoshop plugin for camera raw files. You might want to check to make sure that is updated as well. Here is the adobe support page on it with way more information; https://helpx.adobe.com/camera-raw/kb/troubleshoot-camera-raw-photoshop-photoshop.html
After looking around a bit more, I saw you were not the first one to have this problem. Here’s a support page on adobe I found for the mark IV, which I know isn’t your exact model, but still might be helpful? https://helpx.adobe.com/x-productkb/multi/editing-canon-dual-pixel-raw-cr2.html
I’m also finding a lot of things about your camera model not being able to open raw files from your camera model in CS3…which I know is not your problem, but, it’s interesting that there has been issues with your camera model in photoshop before. If you have lightroom I would try importing it there as well and seeing if it works.
I hope this helps… Like I said I’m not the biggest expert on this but hopefully I was able to shed a bit of light on what the problem may be, or at least give you things to rule out if those aren’t the issues