This error message can come up after turning on the computer, before even showing the bootguard to authenticate. The 0x8? address relates to harddrives. The error message can vary, depending on the nature of hardware failure in the harddisk or the BIOS manufacturer.
The addresses can also vary:
This is a hardware related error message and does not involve any Symantec software like PGP Desktop / Symantec Encrytion Desktop or Symantec Endpoint Encryption.
Since this error indicates a severe hardware failure, the recovery of this error might be impossible or only be possible with the relevant expertise, i.e. HDD manufacturer or a specialised authority.
Refrain from using any tools that write to the disk, the encryption on the disk can get corrupted.