JPGs produced by DxO Optics produce the warning "Bad MakerNotes offset for ThumbnailImage" which can prevent ExifTool saving the file. Example attached.
Windows 7, 64 bit, ExifTool 9.25. Also on OpenBSD with version 8.90.
e.g. exiftool small.jpg | grep Warning
Right. You should be posting this bug report in a DxO forum, not ExifTool.
FAQ number 15 (https://exiftool.org/faq.html#Q15) explains how to deal with problems like this.
- Phil
Ah, sorry, missed that.
Duncan