php - sometimes the error "yii the table for active record class cannot be found in the database" -

i never had problem before last friday! lately (last friday , saturday) pc surf page appears error: the table "devices" active record class "devices" cannot found in database have seen frequent problem did not understand how solve issue. in devices model have correct table name

public function tablename() {     return 'devices'; } 

and in mysql database name same, devices