Declare the property you need to use in the class, or remove the reference to the undefined property.

This check is not avoid for a instance of %Class.

Noncompliant Code Example

Following code will compile, but on runtime the Set obj.test will fail with "PROPERTY DOES NOT EXIST error" message.

Class Sample.NightWatch Extends %RegisteredObject
{
    Property name As %String;
    Property surname As %String;

    Method CreateJon()
    {
        Set obj = ##class(Sample.Person).%New()
        Set obj.name = "Jon"
        Set obj.surname = "Snow"
        Set obj.age = 27 // age is UNDEFINED

        Return obj
    }
}

Compliant Solution

Class Sample.NightWatch Extends %RegisteredObject
{
    Property name As %String;
    Property surname As %String;
    Property age As %Integer;

    Method CreateJon()
    {
        Set obj = ##class(Sample.Person).%New()
        Set obj.name = "Jon"
        Set obj.surname = "Snow"
        Set obj.age = 27

        Return obj
    }
}