Error 0xC80005E1

Value: -939522591 | 0xC80005E1 | 3355444705

What does it mean ?

hrColumnIndexed  
Unable to delete because the column is indexed.
Value: 1505 | 0x05E1 | 0b0000010111100001

Where does it come from ?

FACILITY_NTDSB  
Active Directory Domain Services
Value: 2048 | 0x800 | 0b100000000000

Other Errors for FACILITY_NTDSB