Hi,
That's a corrupted file.
The first thing I'd suspect... also the easiest and cheapest to fix... would be a problem with the memory card or your downloading process.
If I understand correctly, the image looks okay when reviewed on the camera's built in monitor screen, right? Well, that's not conclusive, but it does suggest the the original file was okay. The review image is actually a small JPEG embedded in the RAW file, so it's not 100% certain that there isn't a problem with the camera. But...
I've seen this happen when downloading from a card reader that was connected to the computer via a USB hub.. Eliminating the hub and instead connecting the reader directly to the computer's USB port solved the problem. I now use a computer with a built in card reader (which is both faster and utterly reliable... but like any computer component, could fail).
I've also seen it happen due to the memory card. That might be the card itself actually failing, or simply that it hasn't been regularly formatted in-camera. You might try formatting the card in your computer first, then formatting it again in your camera (you should alwasy format in-camera before shooting with a card... just be sure all images you want to keep are copied off the card first). If that doesn't solve the problem, try a different memory card. They do sometimes "go bad". It also seems to be more common for off-brand cards to fail.
You also might try a different card reader. They sometimes go bad, too.
If you don't already do so, one way to rule out the card reader as the problem would be to try downloading directly from the camera, with the USB cable that was provided with the camera. I don't normally recommend doing that, but it might help you tell if a card reader is at fault.
The reason I usually don't recommend using the USB cable connected to the camera to download images is because the USB socket in the camera is rather easily worn or damaged, and so is that cable. The USB socket in the camera is a rather involved repair, so I normally recommend using a card reader. A separate reader is also usually faster downloading, compared to the USB cable. (Just how fast depends upon the type of connectivity.... USB2, USB3, Firewire 400, Firewire 800, etc.)
However it won't hurt to download directly from the camera, just to test whether or not the card reader or it's connections to the computer are causing the problem.
Also closely inspect the end of the card where the pins fit into it. Look for any broken pins stuck in the card. And use a flashlight to inspect the card socket down in the camera, looking for any bent pins. Hopefully there aren't any. If there are, it might be possible to carefully straighten a bent pin, or the socket might need to be replaced.
If you do the above and pretty much rule out that it's a memory card, card formatting, card reader, or connectivity problem, the next thing to try is "rebooting" the camera. Here is a link to a post on another forum about why and how to do that. Try that first to see if it helps.
If a proper "reboot" doesn't solve the problem, you might want to reinstall the camera's firmware. You can download the firmware and instructions how to install it from here, on the Canon website. In case you have never done this, it's fairly simple, but you do have to be careful to follow the instructions, use a freshly formatted memory card (even if installing the firmware from a location on your computer), need to have the camera's battery(ies) charged up and avoid interrupting the installation. It is possible to "brick" a camera, when installing the firmware. That requires a trip to the service dept.
Honestly, I think rebooting and reinstalling the firmware are both long shots to solve a problem like this. But they are things you can do yourself, might clear some muddled instructions stuck in the cameras memory or repair an instruction set, and they cost nothing to try.
Hope one or the other of these ideas help. If not, you will need to contact Canon Service Dept. and discuss sending it in for them to look at. It might be a connectivity problem or failing component in the camera.
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Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7D(x2), 50D(x3), some other cameras, various lenses & accessories
FLICKR & PRINTROOM
