"Unable to find installable unit" install error for Eclipse plugin

After installing the Openmrs Eclipse Plugin as described on this page

https://wiki.openmrs.org/display/docs/Step+by+Step+Installation+for+Developers

The Dependency installer aborts with the following error message:

Unable to find installable unit with id [org.maven.ide.eclipse.scm.feature.feature.group] in repository [http://m2eclipse.sonatype.org/sites/m2e-extras]

How do I solve this developers?