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The Wildcard instantiated List is unable to receive a value because the use of a wildcard in a generic type parameter means that the type parameter can represent any type. Without specifying a specific type for the list, the compiler cannot guarantee that the value being added is of the correct type for the list, nor can it guarantee that the value extracted from the list is of the correct type. Therefore, it is unsafe to add or extract values from a wildcard instantiated list.