I'm having the same problem on bookworm, for me, I'm using the default eog viewer. There is a new upstream version of libheif available (v1.15.1), there is still time to upload that to bookworm. I'm a DD and I could do an NMU if that is helpful
- Bug#1029668: Cannot read HEIC anymore Dan Jacobson
- Bug#1029668: downgrading heif-gdk-pixbuf:a... Dan Jacobson
- Processed: downgrading heif-gdk-pixbuf... Debian Bug Tracking System
- Bug#1029668: confirmed Hans-Christoph Steiner
- Bug#1029668: Cannot read HEIC anymore James Addison
- Bug#1029668: marked as done (Cannot read H... Debian Bug Tracking System
