OpenPNE3.8.34からOpenPNE3.8.36にアップデートを試みるとmigrateでエラーが出る。

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  Error #1 - Could not find migration class for migration step: 48                                                                                             
 #0 /home/lib/vendor/symfony/lib/plugins/sfDoctrinePlugin/lib/vendor/doctrine/Doctrine/Migration.php(501): opMigration->getMigrationClass('48') 
 #1 /home/lib/migration/opMigration.class.php(109): Doctrine_Migration->_doMigrateStep('down', '48')                                            
 #2 /home/lib/vendor/symfony/lib/plugins/sfDoctrinePlugin/lib/vendor/doctrine/Doctrine/Migration.php(483): opMigration->_doMigrateStep('down', '48')
 #3 /home//lib/vendor/symfony/lib/plugins/sfDoctrinePlugin/lib/vendor/doctrine/Doctrine/Migration.php(328): Doctrine_Migration->_doMigrate(47)   
 #4 /home/lib/task/openpneMigrateTask.class.php(154): Doctrine_Migration->migrate()                                                             
 #5 /home/lib/task/openpneMigrateTask.class.php(105): openpneMigrateTask->migrateFromScript('OpenPNE', Object(sfDatabaseManager))               
 #6 /home/lib/vendor/symfony/lib/task/sfBaseTask.class.php(68): openpneMigrateTask->execute(Array, Array)                                       
 #7 /home/lib/vendor/symfony/lib/task/sfTask.class.php(97): sfBaseTask->doRun(Object(sfCommandManager), NULL)                                   
 #8 /home/lib/vendor/symfony/lib/command/sfSymfonyCommandApplication.class.php(76): sfTask->runFromCLI(Object(sfCommandManager), NULL)          
 #9 /home/lib/vendor/symfony/lib/command/cli.php(20): sfSymfonyCommandApplication->run()                                                        
 #10 /home/symfony(14): include('/home/...')                                                                                           
 #11 {main}