The following error:
is reported in the jbehave plugin of Jenkins. Other users: http://stackoverflow.com/questions/26861855/jenkins-jbehave-plugin-installation-failed-classnotfoundexception-dtkit-testty are encountering this issue which does not work currently. The plugin is currently built with hudson 2.2.0 which is not compatible with Jenkins anymore.
I created https://github.com/jbehave/jbehave-core/pull/118 to fix this issue.
Huge +1 for this. We can't update to the latest xunit plugin until this is resolved.