When multibranch project contains branch with forward slash in the name (for example `feature/foobar`) corresponding Job gets name `feature%2Ffoobar`  from multibranch pipeline plugin.

artifact-manager-s3 plugin later uses this name to generate object key:
https://github.com/jenkinsci/artifact-manager-s3-plugin/blob/master/src/main/java/io/jenkins/plugins/artifact_manager_jclouds/JCloudsArtifactManager.java#L98

As a result generated artifact will be placed in directory hierarchy like this:

projectname/feature%2Ffoobar/1/artifacts/example.txt

However when we try to download this artifact via http url
https://bucketname.s3.amazonaws.com/projectname/feature%2Ffoobar/1/artifacts/example.txt

%2F will be converted to forward slash by browser and request fails with NoSuchKey error from AWS.

When branch name doesn't contain forward slash everything works as expected