Determine the exact format first, then test the matching codec; if the affected files are HEIC/HEIF, install Microsoft’s HEIF and HEVC extensions and restart Photos.
- In File Explorer, select View → Show → File name extensions.
- Record:
- The extension, such as
.jpg, .png, .tif, .heic, or .nef.
- The file’s source: iPhone, camera, scanner, editing software, or download.
- Whether every file of that type fails or only particular files.
- The exact Photos error message.
- Do not diagnose the format solely from the extension. An extension can represent different underlying content, and one format can have multiple extensions; the file’s actual format should match its extension.^1^
Create a small test matrix:
| Test |
Result indicates |
| All files with one extension fail |
Missing format support or codec |
| Only files from one device fail |
Device-specific encoding or transfer issue |
| Only one or two files fail |
Corruption, incomplete transfer, or unusual encoding |
| Open with → Photos works, but double-click fails |
File-association problem |
| Common JPG/PNG files also fail in Photos |
Photos installation or app-data problem |
2. Check codec availability
If the files are .heic or .heif
Install both extensions from Microsoft Store:
- Install HEIF Image Extensions.
- Install HEVC Video Extensions.
- Close and restart Photos, then reopen the file.
Microsoft documents that both extensions can be required even when working only with photos.^2^
If Store installation is unavailable on the managed Windows 365 device, ask the administrator to make those extensions available. As an alternative diagnostic, open the file through the OneDrive website in a browser; OneDrive can preview HEIF/HEVC content even when Windows requires an additional codec to open the downloaded file locally.^3^
In Microsoft Store, search for the exact extension or right-click the file and select Open with → Search the Microsoft Store. Install only an extension or application from a trusted publisher. Codec packs from unrelated download sites should not be the first troubleshooting step.
For camera RAW formats such as .nef, .cr2, or .arw, record the camera model as well as the extension. Support can vary with the specific RAW encoding, not just the filename suffix.
3. Isolate file-association problems
File associations control which application receives a file when it is double-clicked; they do not add decoding support.
- Right-click an affected file.
- Select Open with → Choose another app → Photos.
- If Photos opens it successfully, go to Settings → Apps → Default apps.
- Search for the affected extension, such as
.jpg or .heic.
- Select Photos as its default application.^4^
If Open with → Photos produces the same decoding error, changing the default association will not resolve it; continue with app and integrity checks.
If known-good JPG or PNG files fail in Photos:
- Open Settings → Apps → Installed apps.
- Find Microsoft Photos and select More options (…) → Advanced options.
- Select Repair and retest.
- If Repair does not help, select Reset, then retest.
Repair attempts to fix the application without reinstalling it. Reset returns the app to its default state and can remove its app data.^5^
If only one specialized format fails while ordinary JPG/PNG files open normally, repairing Photos is less relevant than checking that format’s codec.
5. Test image integrity without modifying the original
- Copy one failing file to a local folder such as Pictures. This separates decoding from network, synchronization, or removable-media access.
- Compare its file size with the original source. A zero-byte or unexpectedly small file indicates an incomplete transfer.
- Download or transfer the same image again under a different filename.
- Open both copies in another trusted viewer.
- From that viewer, use Save As or Export to create a new JPG or PNG—do not merely rename the extension.
- Open the exported copy in Photos.
Interpretation:
- Re-exported copy opens: the original likely uses an encoding variant Photos cannot decode, or contains malformed metadata.
- Fresh transfer opens: the first copy was incomplete or damaged.
- Neither original nor exported copy opens, while normal JPG/PNG files do: collect the exact error, extension, source application/device, dimensions, and whether OneDrive web preview succeeds, then escalate to the device administrator or Microsoft support.
References
- Discovering a File's Format
- Photos app Video Editor error: Can’t view this file type | Microsoft Support
- Upload HEIF and HEVC photos and videos to OneDrive | Microsoft Support
- Change Default Apps in Windows | Microsoft Support
- Windows 10