Grails unable to install plugin
The repository changed and it's causing problem for older Grails versions.
See my answer at: Grails Url shortener plugin not getting installed :
Please use
mavenRepo "https://repo.grails.org/grails/plugins"As a repository definition.
http://grails.1312388.n4.nabble.com/Grails-central-repo-seemingly-missing-plugin-versions-td4658720.html