Github user takezoe commented on the issue:
https://github.com/apache/incubator-predictionio/issues/363
It requires to upgrade to Scala 2.11 at first to migrate Akka HTTP.--- If your project is set up for it, you can reply to this email and have your reply appear on GitHub as well. If your project does not have this feature enabled and wishes so, or if the feature is enabled but not working, please contact infrastructure at [email protected] or file a JIRA ticket with INFRA. ---
