sails.js - sails js - error when clean the collections in start up -

in sails application edit config/models.js file follows clean database when lifting application.

  migrate: 'drop',   connection: 'mongodb' 

but when try run application displays following error.

a hook (`orm`) failed load! error: error (e_unknown) :: encountered unexpected error mongoerror: index name: _id_ exists different options 

i using sails version 0.10.5 ,any kind of appreciated.

same here, when have error model orm crashes, @ least have error, mysql don't have error