B-tree node entry <num> has an invalid data length of <num>.

  Explanation:  An entry in a B-tree node was identified as having
  an  invalid  data length.  A data length is invalid if it is LEQ
  zero for a  entry  containing  duplicates  or  NEQ  zero  for  a
  non-duplicate  entry.   The  data  length  is also invalid if it
  extends beyond the end of the b-tree node.