This usually indicates the file is corrupted and cannot be used.
You might want to try transferring the photos to the computer again using DIFFERENT hardware to see if the problem goes away. However, if the problem is the camera card gone bad, then you're out of luck.
I am experiencing the same issue, although not with all my pictures... only with those I imported from December onwards to my catalogue. I have checked using different software if the image is corrupted, and it is not . However, lightrrom keeps saying that it has encountered a problem and I won't be able to make adjustments. Is there any way to know exactly what is the problem that LR is facing? Is there any debug mode?
Incidentally, all this began when I changed from my old MacBook Pro to my new MacPro...
I was able to solve it by checking the WRITE/READ permissions of the entire drive....
If you in OSX you can fix this by doing sudo chmod -R 0777 . within the root directory of your pictures folder/drive