OS: Windows
The recent update to the development version of the JPEG-XL decoder is not backward compatible - to be specifiic, the older decoder has a bug that didn't matter up until now. Alas, all images encoded with 0.10 are not readable anyore, so the lib for XnViewMP needs an update. The respecive fix is 1.5 years old: https://github.com/libjxl/libjxl/issues/1478
Here's the respective libjxl bug ticket, the dev descibes the issue: https://github.com/libjxl/libjxl/issues/2995
Effect: Images encoded with the latest JPEG-XL encoder aren't readable in XnView-MP (or any other app apparantly that uses an older decoder lib).
To reproduce:
1. Encode image with JPEG-XL 0.10
2. Try to read encoded image with XnView containing decoder lib
Actual behaviour (bug): Image is not readable

Expected behaviour: Image is readable