We're seeing the same errors appear in our logs for multiple jobs, and we traced it to the plugin dropping the selector part of the XML config whenever we save the job configuration.
Before saving:
<hudson.plugins.s3.S3CopyArtifact plugin="s3@0.7">
<projectName>reporting-build</projectName>
<filter>**/*</filter>
<target></target>
<selector class="hudson.plugins.copyartifact.ParameterizedBuildSelector" plugin="copyartifact@1.35.2">
<parameterName>ARTIFACT_BUILD_ID</parameterName>
</selector>
</hudson.plugins.s3.S3CopyArtifact>
After saving the job config:
<hudson.plugins.s3.S3CopyArtifact plugin="s3@0.7">
<projectName>reporting-build</projectName>
<filter>**/*</filter>
<target></target>
</hudson.plugins.s3.S3CopyArtifact>
We are not, however, using the workspace cleanup plugin in our build process.
Okay, https://github.com/directhex/s3-plugin/commit/11b22c150957cf6f4ff435b1461f6c80d1b2237d seems to cover all bases for me.