ObjectReader can "deserialize" objects from debuggee. Class Loading: ObjectReader loads classes using the given class loader. If no class loader is supplied, it uses a ProcImageClassLoader, which loads classes from debuggee core or process. Object creation: This class uses no-arg constructor to construct objects. But if there is no no-arg constructor in a given class, then it tries to use other constructors with 'default' values - null for object types, 0, 0.0, false etc. for primitives. If this process fails to construct an instance (because of null checking by constructor or 0 being invalid for an int arg etc.), then null is returned. While constructing complete object graph 'null' is inserted silently on failure and the deserialization continues to construct best-effort object graph. Debug messages: The flag sun.jvm.hotspot.utilities.ObjectReader.DEBUG may be set to non-null to get debug error messages and stack traces. JDK version: JDK classes are loaded by bootstrap class loader and not by the supplied class loader or ProcImageClassLoader. This may create problems if a JDK class evolves. i.e., if SA runs a JDK version different from that of the debuggee, there is a possibility of schema change. It is recommended that the matching JDK version be used to run SA for proper object deserialization.