Zero-byte files and corrupted documents: what they're telling you

Damaged files announce themselves in a handful of shapes: a file listed at 0 bytes, a document opening as squares and symbols, a photo showing a grey box, a folder that looks fine while the files inside will not open. Each shape points at a different place, and knowing which decides what happens next.

The idea behind this page: the symptom tells you where the damage sits. Nothing arrived, so the original may be fine. The bytes arrived but were read wrongly, so they may be intact. The index broke, so files are listed but unreliable. Or the content is damaged, and repair has limits.

The file is there, but it's 0 bytes

A file's size is the amount of data in it: Microsoft documents a file's Length property as returning the size of the current file in bytes, so an entry listed as 0 bytes holds 0 bytes of file data. The usual reason is a copy that never finished: rsync documents how an interrupted transfer leaves behind a partial file with a very recent modified time.^[1][2]

This is the hopeful case. An interrupted transfer, download, or sync leaves a named placeholder holding little or nothing while the original on the other device, card, or cloud copy sits untouched. If it opens there, the fix is a clean re-copy, not recovery.^[2]

Downloads behave the same way: Google documents paused downloads that resume automatically, a Disk full error when there was not enough space to save the file, and Insufficient permissions when Chrome could not save the file to your computer. If a download lands empty, download it again.^[3]

Files that vanished from a drive that still works

The document opens as squares and symbols

Microsoft lists unreadable characters on the screen among the behaviors of a damaged Word document, alongside wrong layout and errors when opening. Its diagnostic separates a bad file from a bad app: open other documents, and if they behave, the problem is likely that one file.^[4]

Squares and symbols are not automatically destruction: Microsoft documents that data converted from one code page to another is subject to corruption because the same data value can encode a different character on different code pages, and a character with no entry in the target gets a default substituted. Boxes are the app failing to map bytes, not the bytes being gone.^[5]

When the file is genuinely damaged, the app has its own repair path: Word for Windows has Open and Repair, from the arrow next to the Open button in the Open dialog. Other apps name it differently, so look in your own app's dialog for its version.^[4]

Photos show as grey thumbnails

The pictures in a photo folder are cached previews, not the images themselves: Microsoft documents that when a thumbnail is needed, Windows first checks the thumbnail cache, and the extractor runs only if the image is missing there or the file is newer than the cached copy. A grey thumbnail speaks about the cache before it speaks about the photo.^[6]

Open the image rather than judging it from the grid. If it opens, nothing was lost. If a freshly generated preview also fails, the file itself is suspect, which fits a truncated or partially written image.^[6]

Can a corrupted SD card be fixed?

The folder looks fine but the files inside are broken

A folder can list files correctly while the data behind them is unusable: the listing and the contents live in different places, and repair works on the first. Apple says Disk Utility can fix errors related to the formatting and directory structure of a storage device, and states plainly that it cannot detect or repair all problems.^[7]

Index damage has a signature: Apple describes overlapped extent allocation as two or more files occupying the same space, at least one of them likely corrupted, with aliases to the affected files in a DamagedFiles folder at the top level of the disk. The directory still reports them; the space they claim is no longer theirs alone.^[7]

Windows draws the same line: chkdsk's /f switch fixes errors on the disk, and Microsoft warns that repairs on FAT file systems usually change the file allocation table and sometimes cause a loss of data. Asked what to do with lost allocation units, answering Y saves each lost chain as a .chk file to check afterwards; answering N fixes the disk and saves nothing.^[8]

The honest summary: repair fixes the index, and damaged content stays damaged. It can stop a shaky structure getting worse, and occasionally strands recoverable pieces. It cannot rewrite bytes that never arrived.^[7][8]

A drive that appears but won't open: the access guide

Repair tools for specific formats

A further layer of tools targets damaged content rather than damaged structure, organized by file format. Ontrack's EasyRecovery Photo is documented as supporting a wide range of digital photo, video, and audio file formats from popular camera brands, with an Add File Type feature for formats not in the list. Not a general fix for every damaged file.^[9]

The safety rule comes from a recovery vendor's own instructions: asked how to recover photos from a drive with bad sectors, Ontrack's answer is to first create an image of the drive, then scan that image, so repeated scanning never touches the failing original. Extending that to a single damaged document is our addition.^[9]

Can corrupted files be recovered?

Which shape is yours

The next move depends on which shape you found: back to the source, to the app's own repair, to the file rather than the preview, or to the drive's index.

Not sure which situation is yours? Guided help walks you through it