pyspark die on second run error

I ran pyspark code the first time it was fine, the second time it dies and show this on every single cell of my zeppelin notebook, and also other notebook that I am running with pyspark, I have to turn on Zeppelin code and restart in order to fix this.

Traceback (most recent call last):
File "/var/folders/zh/dvdnf74d1t9cq78hjjm3xft80000gn/T/zeppelin_pyspark-1462033700144752464.py", line 343, in <module>
sc.setJobGroup(jobGroup, "Zeppelin")
File "/Users/titusfong/spark/python/pyspark/context.py", line 902, in setJobGroup
self._jsc.setJobGroup(groupId, description, interruptOnCancel)
AttributeError: 'NoneType' object has no attribute 'setJobGroup'

this error should be similar to this issue which I don't think is solved yet:
http://apache-zeppelin-users-incubating-mailing-list.75479.x6.nabble.com/Error-about-PySpark-td4988.html
https://issues.apache.org/jira/browse/ZEPPELIN-2449?jql=project%20%3D%20ZEPPELIN%20AND%20text%20~%20%22sc.setJobGroup%22