[Jdk 24] Javaagent failed to start java.lang.ExceptionInInitializerError

[maradanasai]

Describe the bug

We are getting following error for app using jdk 24 with opentelemetry java agent.

Picked up JAVA_TOOL_OPTIONS:  -javaagent:/otel-auto-instrumentation-java-snap-engine/javaagent.jar
2025-08-13 13:03:08.634	
OpenJDK 64-Bit Server VM warning: Sharing is only supported for boot loader classes because bootstrap classpath has been appended
2025-08-13 13:03:08.857	
[otel.javaagent 2025-08-13 07:33:08:855 +0000] [main] INFO io.opentelemetry.javaagent.tooling.VersionLogger - opentelemetry-javaagent - version: 1.33.6
2025-08-13 13:03:09.248	
WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
2025-08-13 13:03:09.248	
WARNING: sun.misc.Unsafe::objectFieldOffset has been called by io.opentelemetry.internal.shaded.jctools.util.UnsafeAccess (file:/otel-auto-instrumentation-java-snap-engine/javaagent.jar)
2025-08-13 13:03:09.248	
WARNING: Please consider reporting this to the maintainers of class io.opentelemetry.internal.shaded.jctools.util.UnsafeAccess
2025-08-13 13:03:09.248	
WARNING: sun.misc.Unsafe::objectFieldOffset will be removed in a future release
2025-08-13 13:03:09.427	
OpenTelemetry Javaagent failed to start
2025-08-13 13:03:09.427	
java.lang.ExceptionInInitializerError
2025-08-13 13:03:09.427	
	at io.opentelemetry.javaagent.tooling.muzzle.AgentTooling.<clinit>(AgentTooling.java:23)
2025-08-13 13:03:09.427	
	at io.opentelemetry.javaagent.tooling.AgentInstaller.installBytebuddyAgent(AgentInstaller.java:151)
2025-08-13 13:03:09.427	
	at io.opentelemetry.javaagent.tooling.AgentInstaller.installBytebuddyAgent(AgentInstaller.java:103)

2025-08-13 13:03:09.427	
	at io.opentelemetry.javaagent.tooling.AgentStarterImpl.start(AgentStarterImpl.java:98)
2025-08-13 13:03:09.427	
	at io.opentelemetry.javaagent.bootstrap.AgentInitializer$1.run(AgentInitializer.java:53)
2025-08-13 13:03:09.427	
	at io.opentelemetry.javaagent.bootstrap.AgentInitializer$1.run(AgentInitializer.java:47)
2025-08-13 13:03:09.427	
	at io.opentelemetry.javaagent.bootstrap.AgentInitializer.execute(AgentInitializer.java:68)
2025-08-13 13:03:09.427	
	at io.opentelemetry.javaagent.bootstrap.AgentInitializer.initialize(AgentInitializer.java:46)
2025-08-13 13:03:09.427	
	at io.opentelemetry.javaagent.OpenTelemetryAgent.startAgent(OpenTelemetryAgent.java:57)
2025-08-13 13:03:09.427	
	at io.opentelemetry.javaagent.OpenTelemetryAgent.premain(OpenTelemetryAgent.java:45)
2025-08-13 13:03:09.427	
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(Unknown Source)
2025-08-13 13:03:09.427	
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
2025-08-13 13:03:09.427	
	at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndStartAgent(Unknown Source)
2025-08-13 13:03:09.427	
	at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndCallPremain(Unknown Source)
2025-08-13 13:03:09.427	
Caused by: java.lang.reflect.InaccessibleObjectException: Unable to make protected final java.lang.Class java.lang.ClassLoader.findLoadedClass(java.lang.String) accessible: module java.base does not "opens java.lang" to unnamed module @4909b8da
2025-08-13 13:03:09.427	
	at java.base/java.lang.reflect.AccessibleObject.throwInaccessibleObjectException(Unknown Source)
2025-08-13 13:03:09.427	
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(Unknown Source)
2025-08-13 13:03:09.427	
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(Unknown Source)
2025-08-13 13:03:09.428	
	at java.base/java.lang.reflect.Method.checkCanSetAccessible(Unknown Source)
2025-08-13 13:03:09.428	
	at java.base/java.lang.reflect.Method.setAccessible(Unknown Source)
2025-08-13 13:03:09.428	
	at io.opentelemetry.javaagent.tooling.muzzle.AgentCachingPoolStrategy.getFindLoadedClassMethod(AgentCachingPoolStrategy.java:115)
2025-08-13 13:03:09.428	
	at io.opentelemetry.javaagent.tooling.muzzle.AgentCachingPoolStrategy.<clinit>(AgentCachingPoolStrategy.java:58)
2025-08-13 13:03:09.428```

Jdk image version: bellsoft/liberica-openjre-debian:24-cds
opentelemetry operator version: 0.131.0 (java auto instrumentation)
opentelemetry java instrumentation version: 2.18.1

### Steps to reproduce

Build spring boot 3.4.x application and attach latest opentelemetry javaagent in dockerfile cmd args. When we run the container, application starts and provide the mentioned logs

### Expected behavior

Should work as expected with Jdk 24 and able to export all signals to collector

### Actual behavior

Getting java.lang.ExceptionInInitializerError error

### Javaagent or library instrumentation version

2.18.1

### Environment

**JDK**:
**OS**:


### Additional context

_No response_

### Tip

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[laurit]

You are using 1.33.6 which was released before jdk 24. You'll have to use a newer version of the agent.

[maradanasai]

@laurit Got it. We are setting up from scratch using latest versions available. Unfortunately, the latest opentelemetry operator is still pointed to very old version for auto instrumentation.

Due to major breaking changes in 2.x, for java it's still using the older version. Not sure why the support for 2.x java agent version is not added

[jaydeluca]

@maradanasai looks like it points to latest to me, are you looking at something different?

[maradanasai]

yes @jaydeluca It default to 1.33.6 and after installing the latest operator, found the same version in Instrumentation CRD

Question - Is it safe to use the latest java image v2.18.1 update the Instrumentation crd considering its a fresh installation?

[maradanasai]

I found some references here
open-telemetry/opentelemetry-operator#3966
open-telemetry/opentelemetry-operator#2542
open-telemetry/opentelemetry-operator#2529

[jaydeluca]

interesting, that looks like an issue with the operator and them being concerned about breaking changes from January 2024. I would recommend updating your configuration to make sure you are using the latest version if you are able to, especially if you are starting from scratch.

[laurit]

@maradanasai you will have to take this up with operator folks. 1.x version of the agent is no longer supported and will not get any more updates. This should be a sufficient reason for them to update the default version of the agent.

[maradanasai]

Got it thanks @laurit