Under what circumstance would you want your child class to avoid serializable if parent is serializable?-Collection of common programming errors

The probable reason this might have happened is that the parent class may have originally been designed not as a parent class, but rather just normal serializable class. So later on, someone created a child class that wasn’t serializable – that doesn’t mean that the parent class has a “design flaw”.

If you may have a particular child class that isn’t Serializable, the only downside is a possible runtime exception if serialization is attempted. If you know that your non-serializable child class won’t ever be serialized by your application, then there’s no real problem.