We are getting Generated Serialization Constructor Accessor error because of Garbage collection in java.Due to memory constrain in perm space GC throws this error,This issue occurs when GC  try to clear ObjectSteamClass .We don't have to worry about this error and this is just information for GC takes time.

[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor3]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor6]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor4]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor5]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor2]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor1]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor8]
[Unloading class sun.reflect.GeneratedSerializationConstructorAccessor7

Possible Reasons : 

  1. More IO operations
 2. Heavy use of reflections and serialization

 How to Avoid this Error:

1. Increasing perm size could stop this error