B-tree node not found at dbkey <num>:<num>:<num>

  Explanation:  A B-tree index node  was  expected  at  the  given
  dbkey,  but was not found.  The pointer to the duplicate node in
  the B-tree is probably corrupt.

  User Action:  Ascertain if the  index  is  corrupt  by  manually
  verifying  related  index  nodes  after  dumping  pages  of  the
  database.  If the index is corrupt, rebuild it.