Error messages and what they mean
Each app words a broken file its own way, and one message can cover several problems.
| App | Message | Possible cause |
|---|---|---|
| Media Player or Movies & TV on Windows | Error 0xc00d36c4, "This file isn't playable" | Unsupported format, wrong extension or a damaged file |
| Media Player or Movies & TV on Windows | Error 0xc00d5212, "This item was encoded in a format that's not supported" | A missing codec |
| Google Photos and other Android galleries | "Can't play video" or a close variation | Damage, an unsupported codec or an unfinished download |
| Photos on iPhone | "Unable to Load Video" | The full-quality copy in iCloud didn't download |
| QuickTime Player on a Mac | "The file isn't compatible with QuickTime Player" | An unsupported codec or a damaged file |
| VLC | "Your input can't be opened", or no picture and no message | Probable damage, since VLC decodes most formats |
The codec error and the iPhone message don't point to damage. The others can mean either, so test the file before you pay for a repair.
Damaged, missing a codec, or unfinished?
Three tests sort it out.
Play it in VLC. VLC brings its own decoders for H.264, H.265 and most common formats. If the file plays in VLC, the trouble sits with your first player, which lacks a codec. Sound over a black picture means the same thing. H.265 is a common case: Windows' own players need Microsoft's HEVC Video Extensions to show it.
Compare the size, and check where the file lives. A copy or download that stopped short comes out smaller than the original, so copy or download it again if you still have the source. A cloud file can also sit online while it looks local. OneDrive shows a cloud icon on online-only files and fetches them when you open them, which fails without an internet connection. On an iPhone, "Unable to Load Video" means the phone couldn't fetch the full-quality copy from iCloud.
Check the length. The index stores the video's duration. A file with a large size, no length in its properties and no player that opens it, VLC included, has lost its index. Recordings cut off by a dead battery, a crash, a pulled card or a power cut end up this way.
A quick decision guide
| You see | Probable cause | Next step |
|---|---|---|
| Sound with a black picture | Player lacks the video codec | Use VLC, or add the HEVC Video Extensions |
| Plays in VLC, fails elsewhere | Codec support | Keep VLC, or convert a copy |
| Smaller than the original, or stops at the same spot | Copy or download ended short | Copy or download it again |
| Cloud icon, or an iPhone that can't load it | File isn't on the device yet | Download it first |
| Large file, no length, nothing opens it | Missing index | Run the checker on this page |
| 0 KB | No data in the file | Nothing to repair |
Damage the tool can repair
The tool repairs one kind of damage: an MP4, MOV, M4V or 3GP recording that lost its index because recording stopped before the camera finished the file. The video has to be H.264 or H.265, and the sound AAC. Many phones, dashcams, drones and action cameras write the index when you stop recording. A battery that dies or a card that comes out first leaves the footage in place with no index, and the repair writes a new one around it.
The tool can't help with these:
- Deleted videos. The tool repairs files you have; an undelete program has to bring a deleted file back first.
- Footage that was overwritten or never written, such as a file that is empty or all zeros.
- AVI, MKV, TS and WebM files, which the tool doesn't support yet.
- Videos hidden by vault or "hide video" apps, which the tool can't decrypt.
Repair a damaged MP4 or MOV
- Choose the damaged file in the tool above. The tool reads it from your own disk, with no upload.
- Read the result of the free check. It says whether the file holds footage the tool can rebuild.
- Some cameras don't repeat their settings inside the footage. For those files the tool asks for a reference clip: any healthy video from the same camera at the same settings. The reference also brings the sound back when it's missing.
- Watch five seconds of your own footage in the free preview, at reduced quality with a watermark.
- Download the full video with a plan: one video, three months or a year, and you can cancel anytime. If the repaired video doesn't play, you get a refund.
The tool re-encodes nothing. The repaired file holds the camera's own video and sound data byte for byte, with a new index written around it.