Solving 'Plugin org.apache.maven.plugin could not be found', or 'Could not find artifact in artifactory-release'

We recently purchased an Artifactory 3.4 pro license where I work, and I've been setting it up to work with Jenkins.

Unfortunately, Jenkins was failing when it was trying to download an Apache Maven dependency with a virtual repository I'd created.

Either I'd forgotten a step or it'd been already setup when I'd been playing with the evaluation version, but I'd failed to link a huge online maven 2 repository to my virtual repo.

[NOTE: I was also trying to update the .m2/settings.xml file and that wasn't working either in Jenkins. ]

If you're getting messages in your Jenkins console output like this :

[ERROR] Plugin [...] or one of its dependencies could not be resolved: Failed to read artifact descriptor for [...]: Could not find [...] in artifactory-release

and have setup your Jenkins job (AKA job) to work with Artifactory, this might be the issue.

Once I had my virtual repository serving artifacts from my local repository, I failed with adding a remote repository - and one of the most crucial : maven2.

In my case  org.apache.maven.plugins:maven-clean-plugin:2.5, wasn't found.

I added a new remote repository pointing to : http://repo.maven.apache.org/maven2/

Then I went back to my virtual repo and added the Maven repo under Edit Virtual Repository > Basic Settings > Repositories.

I launched the build again and the error went away.