In the below page, it mentioned like the property javaSerializationFormatEnabled default value is false.
SECTION A:
By default it’s disabled, we need to set it to true if we need to enable it.
SECTION B:
In below page it’s mentioned default values as true.
SECTION B is true for only older versions?
Exactly. As the documentation states, it is true for 7.6.11+, 7.7.6+, and 7.8.1+
You can also see that in their respective documentations, e.g. here:
Thanks @tmetzke . What’s the reason for that change? Earlier versions (7.6.11+, 7.7.6+, and 7.8.1+) has default value as true, and 7.13 is having default as false.
It is usually done to preserve the old behavior for customers (which was that it is enabled by default) so applications don’t break when they are patched.
We then announced a change of the default for a later minor version (I believe it was 7.9), so customers have enough time to prepare their applications before they do a minor version upgrade. In this case, it is a potential security risk to have it enabled and that’s why we went with the default being set to false from that version on.
Great. Thanks 
You’re welcome, thanks for asking for clarification 
