Lease signed by agent for trustees as owners of the property was invalid because the power of attorney did not have the notice required by 20 Pa.C.S. § 5601(c) or the acknowledgement of the agent required by 20 Pa.C.S. § 5601(d). The immunity provision of 20 Pa.C.S. § 5608(d) was not relevant because at issue was the validity of an option under a lease and there was no liability being asserted against the agent or the parties dealing the agent. Motee v. Bazzanza, Trustee, 395 EDA 2025 (Pa. Super. 10/15/2025).