error readying logical area with dbid <num>

  Explanation:  An error occurred when  an  attempt  was  made  to
  ready  the  given  logical  area.   This  could  be because of a
  corruption in the RDB$SYSTEM area.

  User Action:  Check  if  there  are  conflicting  users  of  the
  database.  If so, verify this portion of the database when there
  are no conflicting users.  If there is a corruption that  causes
  this  error, correct the error with the RMU Restore command, and
  verify the database again.