The JPEG to HEIC/HEIF encoding doesn't seem to work.
Xnview MP 0.99.7 64bits (Jan 13 2022)
Windows 10 Pro x64 21H2 19044.1503
I tried to convert a large folder of couple thousands of jpeg files. XnView doesn't report any errors during conversion process, it saves all the heic files during the conversion, but the output files are corrupted or wrong type, since no program can read them.
XnView itself can't read the output files, neither can ImageGlass. If I upload the output files to google drive, it can't show the pictures.
Despite most of the files were corrupted, very few (literally one in a thousand) were successfully converted. XnView, ImageGlass and Google all read these few files successfully.
This is a screenshot from XnView MP Thumbnails view, there is one HEIC picture that can be read:

However, as can be seen from the screenshot above, most other pictures can't be viewer in XnView.
ImageGlass gives also error message.


I have attached some sample files of the converted files in the attached ZIP file.
image1477.heic is an example of a working file (indeed one of very few out of thousands I tried)
image1478.heic is a typical corrupted file
These were the HEIC conversion settings:


Thanks for your time and effort with this great program. Let me know if I can help somehow with troubleshooting this bug and get the HEIC conversion working.