Troubleshooting
Problem
A library known as xStream is used for XML serialization and de-serialization. This library is used throughout ContentCortex. Internally, xStream makes use of a utility called the Unsafe class. the Unsafe class has been marked for deprecation in the future.
Symptom
The following warning messages may be observed when using tools that invoke xStream, such as configTool.
WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
WARNING: sun.misc.Unsafe::objectFieldOffset has been called by com.thoughtworks.xstream.converters.reflection.SunUnsafeReflectionProvider (file:/opt/IBM/ContentSearchServices/CSS_Server1/lib/xstream.jar)
WARNING: Please consider reporting this to the maintainers of class com.thoughtworks.xstream.converters.reflection.SunUnsafeReflectionProvider
WARNING: sun.misc.Unsafe::objectFieldOffset will be removed in a future release
Cause
The JVM being used to run the program in question has marked Unsafe for deprecation and is using a version of the xStream library which is using the Unsafe class.
Environment
This behavior is expected when using JDK 23 and above on all operating systems.
Diagnosing The Problem
You will see "sun.misc.Unsafe has been called" in the log messages of the program that is being executed.
Resolving The Problem
Configure your JVM with this parameter to suppress the warning until xStream has removed the class from their functions:
--sun-misc-unsafe-memory-access=allow
Document Location
Worldwide
Was this topic helpful?
Document Information
Modified date:
08 May 2026
UID
ibm17272389