I tried someting.
1. I used external power for the usb hdd. it does not work. ( My usb device is Seagate Expansion HDD Disk and sandisk SSD 240 GB)
i tried with Wd myPassport 500gb SSD its working .
i rolback box to 6.1 image . all of them are working perfectly.
I think the problem about some missing usb drive.
Because of when i update 6.1 to 6.2 from box menu it was working for first restart.
After Device dedected new update and i instaled some new update from enigma menu. But it does not work. stayed on boot.
so
i had to flash by usb device (6.2) ..Now the problem continues.
Best regards.