NoClassDefFoundErrors after updating

After updating to latest Jenkins and artifact-manager-s3, I see an unreadable message for pretty much every single build on the manage old data page:

NoClassDefFoundError: com/google/common/base/Supplier, ConversionException: Could not call io.jenkins.plugins.artifact_manager_jclouds.JCloudsArtifactManager.readResolve() : Missing provider field : Could not call io.jenkins.plugins.artifact_manager_jclouds.JCloudsArtifactManager.readResolve() : Missing provider field ---- Debugging information ---- message : Could not call io.jenkins.plugins.artifact_manager_jclouds.JCloudsArtifactManager.readResolve() : Missing provider field cause-exception : com.thoughtworks.xstream.converters.reflection.ObjectAccessException cause-message : Could not call io.jenkins.plugins.artifact_manager_jclouds.JCloudsArtifactManager.readResolve() : Missing provider field class : io.jenkins.plugins.artifact_manager_jclouds.JCloudsArtifactManager required-type : io.jenkins.plugins.artifact_manager_jclouds.JCloudsArtifactManager converter-type : hudson.util.RobustReflectionConverter path : /flow-build/artifactManager line number : 792 -------------------------------

Additionally, attempting to validate the s3 bucket configuration on the settings page gets me a "NoClassDefFoundError:com/google/common/collect/Sets"

This is obviously breaking the ability to fetch artifacts from old builds, and new builds are dumping their artifacts right on the local file system rather than going to S3.