What is the test for a motion to amend a complaint to quiet title based on adverse possession?

Here, Gonsalves makes no attempt to show that his 12 new causes of action were within the scope of the trial court's order granting him leave to amend his original complaint to quiet title based on adverse possession. Thus, he has failed to show any error in the trial court's ruling regarding those 12 causes of action. (See Zipperer v. County of Santa Clara (2005) 133 Cal.App.4th 1013, 1020 [on appeal from the sustaining of a demurrer without leave to amend, " 'the plaintiff bears the burden of demonstrating that the trial court erred' "].)