Getting java.lang.NullPointerException at org.apache.thrift.transport.TSocket.open(TSocket.java:209) while creating hiveContext in Zeppelin.

[#1]

I had installed HDP 3.0 which has Spark 2.3.1. I was running sql commands in Zeppelin notebook successfully but suddenly Windows update restarted the machine. When I opened the Zeppelin notebook again and ran the first command

%spark2
val hiveContext = new org.apache.spark.sql.SparkSession.Builder().getOrCreate()

I got following error logs: - 

java.lang.NullPointerException at org.apache.thrift.transport.TSocket.open(TSocket.java:209) at org.apache.zeppelin.interpreter.remote.ClientFactory.create(ClientFactory.java:51) at org.apache.zeppelin.interpreter.remote.ClientFactory.create(ClientFactory.java:37) at org.apache.commons.pool2.BasePooledObjectFactory.makeObject(BasePooledObjectFactory.java:60) at org.apache.commons.pool2.impl.GenericObjectPool.create(GenericObjectPool.java:861) at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:435) at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:363) at org.apache.zeppelin.interpreter.remote.RemoteInterpreterProcess.getClient(RemoteInterpreterProcess.java:62) at org.apache.zeppelin.interpreter.remote.RemoteInterpreterProcess.callRemoteFunction(RemoteInterpreterProcess.java:133) at org.apache.zeppelin.interpreter.remote.RemoteInterpreter.internal_create(RemoteInterpreter.java:165) at org.apache.zeppelin.interpreter.remote.RemoteInterpreter.open(RemoteInterpreter.java:132) at org.apache.zeppelin.interpreter.remote.RemoteInterpreter.getFormType(RemoteInterpreter.java:299) at org.apache.zeppelin.notebook.Paragraph.jobRun(Paragraph.java:407) at org.apache.zeppelin.scheduler.Job.run(Job.java:188) at org.apache.zeppelin.scheduler.RemoteScheduler$JobRunner.run(RemoteScheduler.java:307) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748)

I am clueless. Request you to help me out of this issue. Thanks.

[#2 · Accepted solution]

I restarted all the interpreters in settings section like :-

spark2,
angular
jdbc
livy2
md

and saved it.
Then re-run the code and it was successful. Thanks.