Lightroom 4 “Files Could Not Be Read”

Last night, I was working in Lightroom 4.1, trying to import a number of video and photo files from a SanDisk Extreme IV 16GB compact flash (CF) card used early that night with a Canon 5D Mark III, but kept getting this message on two of the HD MOV files: “The following files were not imported because they could not be read.” I tried several times, and kept getting the same error. Trying not to freak out, I tried to figure out what could be wrong. I came up with several theories: 

• The files got corrupted and could not be read because they did not finish recording properly. I was having some problems with third-party LP-E6 batteries that would just turn off my camera without any warning. Three bars, two bars, and then boom! The camera turns off. I though I would save a few dollars by getting non-OEM LP-E6 batteries, but this turned out to be a crummy idea. It also doesn’t charge properly, causing my Canon battery charger to go from 1 flash (very empty) to 2 flashes (half full) to 3 flashes (nearly full) to blinking nonstop (error) instead of lit up green and not flashing (full). Anyway, could it be that a faulty battery prevented the file header from being completed properly? The problem with this theory is that I would have thought the header would have been written at the beginning of the recording process. What kind of data is written to the buffer? What process occurs at the end of the recording to wrap it up?
• I didn’t properly format the CF card before recording new content on it. This seemed somewhat unlikely to be the source of the problem, as I exclusively use these CF cards only on my Canon 7D and 5D Mark III, so I expected that the file system is compatible even if I forgot to format it. Also, this seemed strange because most of the videos came off the card just fine, but I just had these two files that seemed “corrupted.”

What else could have gone wrong? Please leave a comment if you’ve had a similar experience or theories. Or even better, if you have a solution!

Update: Just found out the real reason for my problems. The external hard drive I was trying to write to didn’t have enough space! I was trying to copy MOV files (each 4GB+) to a drive with 3GB left. I deleted some unneeded files, and tried again. Lightroom had no problems ingesting the files this time. Oops! Of course, it would have been much better had the error message been, “The volume is full. Cannot copy these files to volume.” In any case, I’ll leave this post up in case it helps anyone out!