*why display this error *
2018-09-17 11:49:19 ERROR ReceiverTracker:91 - Receiver has been stopped.
Try to restart it.
org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in
stage 81.0 failed 1 times, most recent failure: Lost task 0.0 in stage 81.0
(TID 81, localhost, executor driver): java.lang.AbstractMethodError