What is the burden of proving that a property is not encumbered by a valid lien?

Appellants argue that it was the Muse Plaintiffs' burden at trial to prove that the property was not encumbered by a valid lien. But even if this were true, appellants cannot shift their burden on appeal. "'A judgment or order of the lower court is presumed correct. All intendments and presumptions are indulged to support it on matters as to which the record is silent, and error must be affirmatively shown. This is not only a general principle of appellate practice but an ingredient of the constitutional doctrine of reversible error.'" (Denham v. Superior Court (1970) 2 Cal.3d 557, 564;

Page 13