A deficiency remained after a deed of trust sale, so the creditor sought to pursue that debt in bankruptcy court. The court ruled that the creditor lacked standing because it had not obtained a deficiency judgment under Nebraska law and therefore was barred from bringing "an action" to recover the balance due. However, the creditor is likely entitled to pursue its non-judicial remedies under the UCC, and the bankruptcy court would go forward with a trial on the creditor's motion for relief from stay to do so.