Black screen after preboot login after upgrading to DE 7.2.9.HF3 and Agent 5.6.3
I had this issue with several systems in my environment with 1709 and we discovered its due to boot partition corruption. The fix was to decrypt the disc offline using DETech and then using a Windows disk or MS DaRT disc run command prompt following the below instructions.
Run DISKPART
DISKPART
List disks if there are multiple disks
LIST DISK
Select the primary disk
SEL DISK #
List the volumes and partitions to see the EFI boot partition
LIST VOL
Select the EFI partition which should be Fat32
SEL VOL #
Assign it a letter
ASSIGN LETTER=F:
Exit the DISKPART
EXIT
Change disk to the assign partition
F: or cd F:
Format the EFI Partition
format F: /FS:FAT32
Fix the boot settings
bcdboot C:\Windows /s F: /f UEFI
Corporate Headquarters
6220 America Center Drive
San Jose, CA 95002 USA