Simplify the following text for a Grade 9 native English-speaking person.
Original: It is often mistakenly considered to be a formal fallacy , but it is not , because a false analogy consists of an error in the substance of an argument ( the content of the analogy itself ) , not an error in the logical structure of the argument .
Simplified: It is an informal fallacy because the error is about what the argument is about , and not the argument itself .