source for <str> "<str>" missing in module "<str>" - routine not
  extracted

  Explanation:  RMU Extract uses the original SQL source text from
  the  RDB$ROUTINE_SOURCE  column in the RDB$ROUTINES system table
  when you specify the Item=Modules qualifier.   This  source  has
  been removed, probably to restrict users from viewing the source
  for the stored module.

  User Action:  If the module is created by the  RdbWEB  software,
  then  this  is  the  expected  behavior;  regenerate  the module
  instead of using RMU Extract.  If this  is  a  customer  defined
  module, then investigate why the source is missing.