I use 6.1 OpenHDF an today update via HDfreaks console to version 176.
Box restart an not booting,Red not flash but light.Rescue mode ok but not possible reflash
this is error
[*] Running './recovery'
[*] Options '-v -b'
[*] Downloading 'http://dreamboxupdate.com/download/recovery/dm520/release/dreambox-image-dm520.tar.xz.sig'
[*] Downloading 'http://dreamboxupdate.com/download/recovery/dm520/release/dreambox-image-dm520.tar.xz'
[*] Verifying signature of 'dreambox-image-dm520.tar.xz'
gpgv: Signature made Tue Jan 10 12:03:29 2017 UTC using RSA key ID A07683D3
gpgv: Good signature from "Dreambox DM520 Recovery <dm520@recovery.dreambox.de>"
[*] Mounting '/dev/ubi0_0' to '/mnt'
/mnt/etc/recovery/backup-hooks.d/fstab.sh: line 4: can't create /mnt/etc/enigma2/fstab.bak: Read-only file system
[*] Unmounting '/mnt'
umount: can't unmount /mnt: Device or resource busy
Fatal: Failed to execute './recovery'