fix compute bdf scoring

models/financial_contract_guarantee.py

@@ -202,6 +202,8 @@ class FinancialContractGuarantee(models.Model):
     def _compute_guarantee_data(self):
         for guarantee in self:
             last_line = guarantee.line_ids.sorted("line_date", reverse=True)
+            if last_line:
+                last_line = last_line[0]
                 guarantee.update({"bdf_scoring": last_line.bdf_scoring})
 
     @api.depends(