s3Upload fails with duplicate class definition of com.amazonaws.event.ProgressEvent

[VladimirKovac-FS]

Hello,

I've been getting this error for plugin version 1.43, Jenkins version 2.277.4:

java.lang.LinkageError: loader (instance of  hudson/ClassicPluginStrategy$AntClassLoader2): attempted  duplicate class definition for name: "com/amazonaws/event/ProgressEvent"
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(Unknown Source)
	at jenkins.util.AntClassLoader.defineClassFromData(AntClassLoader.java:1155)
	at hudson.ClassicPluginStrategy$AntClassLoader2.defineClassFromData(ClassicPluginStrategy.java:718)
	at jenkins.util.AntClassLoader.getClassFromStream(AntClassLoader.java:1326)
	at jenkins.util.AntClassLoader.findClassInComponents(AntClassLoader.java:1377)
	at jenkins.util.AntClassLoader.findClass(AntClassLoader.java:1342)
	at jenkins.ClassLoaderReflectionToolkit._findClass(ClassLoaderReflectionToolkit.java:107)
	at hudson.ClassicPluginStrategy$DependencyClassLoader.findClass(ClassicPluginStrategy.java:637)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at jenkins.util.AntClassLoader.findBaseClass(AntClassLoader.java:1406)
	at jenkins.util.AntClassLoader.loadClass(AntClassLoader.java:1085)
	at java.lang.ClassLoader.loadClass(Unknown Source)
Caused: java.lang.BootstrapMethodError
	at de.taimos.pipeline.aws.S3UploadStep$RemoteUploader.invoke(S3UploadStep.java:626)
	at de.taimos.pipeline.aws.S3UploadStep$RemoteUploader.invoke(S3UploadStep.java:481)
	at hudson.FilePath.act(FilePath.java:1164)
	at hudson.FilePath.act(FilePath.java:1147)
	at de.taimos.pipeline.aws.S3UploadStep$Execution.run(S3UploadStep.java:463)
	at de.taimos.pipeline.aws.S3UploadStep$Execution.run(S3UploadStep.java:295)
	at org.jenkinsci.plugins.workflow.steps.SynchronousNonBlockingStepExecution.lambda$start$0(SynchronousNonBlockingStepExecution.java:47)
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
	at java.util.concurrent.FutureTask.run(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)

• The build is setup via a scripting pipeline.
• The path to upload is a directory with multiple child folders and files.
• Starting the upload via CLI works as intended.
• AWS credentials are correct.
• The only Amazon-related plugin installed is Pipeline: AWS Steps and its dependencies. I thought at first some other plugin may be loading a different version of ProgressEvent but that wasn't the case.

Did anyone encounter anything similar? I can't find any good resources on what else to check and how to fix this issue. Is it possible multiple uploads load the same class and cause a collision?

[VladimirKovac-FS]

In case somebody runs into the same issue, we still haven't solved it but instead avoided it by replacing the plugin with a direct batch call to AWS CLI:

withCredentials([[$class: 'AmazonWebServicesCredentialsBinding', accessKeyVariable: 'KEY_ID', credentialsId: 'CRED-ID', secretKeyVariable: 'ACCESS_KEY']])
{
	echo bat(returnStdout: true, script: "aws s3 cp --recursive ${FOLDER_FROM} ${FOLDER_TO}").trim()
}

If on Windows, make sure that the Jenkins service runs with a Windows user that has privileges to access FOLDER_FROM and call aws s3 cp.