Hi, The package validation function AcpiNsCheckPackage() in file nspredef.c requires that packages be non-empty: /* The package must have at least one element, else invalid */ if (!Count) { ACPI_WARN_PREDEFINED ((AE_INFO, Data->Pathname, Data->NodeFlags, "Return Package has no elements (empty)")); return (AE_AML_OPERAND_VALUE); } I don't see, from the ACPI specification, why packages for predefined ACPI objects must be non-empty. Where does this requirement come from? Best regards, Grégoire Sutre