(I only know a little bit about Canon)
That's Photoshop "Camera RAW"/Canon RAW compatibility problem. The solution is to update the Photoshop camera raw. I had same problem before.
Or if you're a Canon user, you can try following workarounds in the Canon's DPP(Digital Photo Professional).
1. Select one, click Tools in Menu and select "Transfer to Photoshop" in drop-down box. If not work try #2.
2. Select one and open it. Click File in Menu and select "Convert and save", save it as TIF format. Then it can be opened in the Photoshop.