Which repository do you use? The issue should be fixed in 0.9.1 and 1.0.0
https://spark-project.atlassian.net/browse/SPARK-1052 <https://spark-project.atlassian.net/browse/SPARK-1052> There's an old repository https://github.com/apache/incubator-spark and as Spark become one of top level projects, it was moved to new repo: https://github.com/apache/spark The 0.9.1 version hasn't been released yet, so you should get it from the new git repo. -- View this message in context: http://apache-spark-user-list.1001560.n3.nabble.com/java-lang-ClassNotFoundException-spark-on-mesos-tp3510p3551.html Sent from the Apache Spark User List mailing list archive at Nabble.com.