Github user pferrel commented on the issue:
https://github.com/apache/incubator-predictionio-template-java-ecom-recommender/pull/6
Also the build.sbt locks people into the latest versions of Spark, etc. So
this template will no longer work with services installed with pio-0.11.0
including the Scala version. Existing users should be warned about this--do not
upgrade pio unless you are willing to upgrade scala, and other services. In the
case of ES it means wiping the meta store, which in turn means they must `pio
export` before upgrading and `pio import` into new apps to get metadata
re-created in ES5.
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