If you get this error, there are three things you can do.
1) Cycle power and see if this clears the error.
2) Use the command TPCPZ, and cycle power, to reset the drive to factory defaults. (SAVE PROGRAMS FIRST!!)
3) Remove the battery (see FAQ entitled "Battery Replacement for BDHX,BLX,BLHX,PDHX, X150")