After upgraded to DSM 6.2.2 and moments 1.3.2, the face recognition is empty , and concept category only has child.   I found thus shoud be a bug of photo detection plugin. So, there is the way to fix it: 1. enable SSH, and disable Moments. 2. replace /var/packages/SynologyMoments/target/usr/lib/ with my attachment.  3. enable Moments. (maybe need to reindex.) everything is fine. Enjoy~   libsynophoto-plugin-detect