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"What likely changed is not Pixillion’s basic HEIC support, but either the HEIC files themselves or the decoding path on your PC. Pixillion’s own help says a “Load failed” message appears when it thinks the image is corrupt or is actually a different file format disguised as an image, and it supports HEIC/HEIF only for still images on Windows.
Most likely reasons
- The files may now be damaged during transfer. If the HEICs are being copied from the iPhone through iCloud, a cable import, or another sync tool, the transfer process itself can produce files that look valid but won’t decode correctly.
- Your Windows HEIC/HEVC support may have changed. Microsoft’s HEIF Image Extensions are the usual decoder path on Windows, and Windows HEIC viewing depends on that stack plus HEVC support in some setups.
- The photos may be newer HEIC variants. There are reports that newer iPhone-originated HEIC files can behave differently from older ones in some apps and decoders, which would fit a “used to work, now it doesn’t” pattern.
What to check
- Test the same file in another app such as Windows Photos, iCloud Photos, or another HEIC viewer. If it fails everywhere, the file is probably bad; if it only fails in Pixillion, the app or its decoder path is the issue.
- Check whether Windows HEIF/HEVC components are installed and working. If those were removed, changed, or broken by an update, HEIC handling can stop working even if the file is fine.
- Try a freshly transferred HEIC from the iPhone. If old files work and new ones do not, the issue is more likely the transfer method or a format change in the newer files.
Practical fix
If you just need reliable conversion right now, try a different converter or first verify the file opens in a viewer that explicitly supports HEIC/HEIF. Pixillion’s documentation also suggests that “Load failed” means the source is corrupt or not really the expected format, so if every file now fails, I’d suspect the transfer pipeline or decoder setup before Pixillion itself."