UDF Output Not able to STORE in SparkStreaming mode

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Crashes with java.lang.RuntimeException: org.apache.pig.backend.executionengine.ExecException: ERROR 0: Exception while executing [POUserFunc (Name: POUserFunc(org.apache.pig.tutorial.ToLower)[chararray] - scope-3 Operator Key: scope-3) children: null at []]: java.lang.NullPointerException