Plugin org.jboss.tools.common.reddeer has wrong value for "Bundle-RequiredExecutionEnvironment:" in Manifest file. There is JavaSE-1.6, but there should be at least JavaSE-1.7, because in file "org.jboss.tools.common.reddeer.utils.FileUtils" is used packege "java.nio.file", which was introduced in JavaSE-1.7 - https://docs.oracle.com/javase/7/docs/api/java/nio/file/package-summary.html .

With JavaSE-1.6 it shows an error under devstudio with JDK 9.