Solution to fix update fail from 6.2.4 to 6.2.4-2
My solution is rollback to 6.2.4
* Please backup the data if it is important !!
(I suppose without data loss after rollback)
1. login the console with root (without password)
2. mount /dev/md0 /mnt
3. rm -rf /mnt/.syno
4. http://NAS-IP:5000
Select "Migration: Keep my data and most of the settings"
Install original pat (DSM_DS3615xs_25556.pat) # 271 MB