Error building some of the projects

I’m getting an error in the Maven build. Access denied to http://maven.restlet.org/org/webjars/bower/graphlib/maven-metadata.xml. Error code 403, Forbidden.

Any ideas?

This is not something we’ve seen before.

What specifically are you trying to build, and how? (which project, build commands used, operating system etc)
Was it an intermittent problem or still occurring on later tries?