FWIW, I see these a lot. Common causes have already been given in other answers, you need to determine cause if possible by swapping all hardware involved, reader, cables, different USB port etc.. If it's the memory card itself there's not much you can do, NAND write/erase cycles are finite so may simply be wear.

What I like to add though is that this type of damage can often be repaired. If image displays only partially there's two things I always check:

• File size compared to similar intact files. If you miss for example about 1/3rd of the image AND file size is also about 1/3rd less than comparable intact image then data is simply missing

• Open file in HxD, sometimes you'll find 1/3rd of data simply being zeros or repeating byte pattern (FF FF FF etc.).

If image damage can not be explained by above, the image may be repairable. I made software that first of all removes 'illegal' byte combinations that may cause rest of the image to be grey. In this example there are 4 corrupt areas:

We can now see image actually continues. By removing remaining corrupt data, and replacing it by zeros it is often possible to repair the image to a degree. Rest damage can then be repaired using a photo editor. Example repair:

https://youtu.be/IUUvWXMtfuY

Too late for OP probably, I hope it can help someone else some day.

FWIW, I see these a lot. Common causes have already been given in other answers, you need to determine cause if possible by swapping all hardware involved, reader, cables, different USB port etc.. If it's the memory card itself there's not much you can do, NAND write/erase cycles are finite so may simply be wear.

What I like to add though is that this type of damage can often be repaired. If image displays only partially there's two things I always check:

• File size compared to similar intact files. If you miss for example about 1/3rd of the image AND file size is also about 1/3rd less than comparable intact image then data is simply missing

• Open file in HxD, sometimes you'll find 1/3rd of data simply being zeros or repeating byte pattern (FF FF FF etc.).

If image damage can not be explained by above, the image may be repairable. I made software that first of all removes 'illegal' byte combinations that may cause rest of the image to be grey. Once we remove these the image can often be decoded all the way though be it distorted:

We can then further repair the image by manipulating the file at the byte or MCU level:

https://youtu.be/A33zn_sgm30

Too late for OP probably, I hope it can help someone else some day.