There is no sequence for account.bank.statement.line to prefill the field name (Communication), better remove it.
'currency_id': fields.many2one('res.currency', 'Currency', help="The optional other currency if it is a multi-currency entry."),
}
_defaults = {
- 'name': lambda self,cr,uid,context={}: self.pool.get('ir.sequence').get(cr, uid, 'account.bank.statement.line'),
'date': lambda self,cr,uid,context={}: context.get('date', fields.date.context_today(self,cr,uid,context=context)),
}