Quick summary
Some photos have a file extension that doesn't match what the file really is. For example, an iPhone HEIC or a PNG renamed to .jpg. Imagen checks this for JPEG and TIFF files.
How to fix this
- Find photos that were renamed by hand, or saved from a phone, a messaging app or a cloud service.
- Renaming a file doesn't change its format. To convert a photo, open it in an editing app, and use Export or Save As JPEG.
- HEIC, PNG, PSD and GIF aren't supported. Converting them only works if the original camera metadata is kept.
- Remove or replace those files, and create the project again.
- Imagen supports RAW, DNG, JPEG and TIFF files. JPEG and TIFF photos have to be the originals from your camera, not exported from another app.