Open the neo4j.conf at /etc/neo4j/neo4j.conf and replace the line #dbms.security.procedures.whitelist=apoc.coll.*,apoc.load.* with dbms.security.procedures.whitelist=apoc.coll.*,apoc.load.*,apoc.* and save it.
Restart the Neo4j service by issuing the command systemctl restart neo4j
Note: Make sure that you have the right version of apoc jar downloaded. I'm using the neo4j version 3.5.5 and the apoc jar version I'm using is apoc-126.96.36.199-all.jar . Also make sure that you have the dbms.directories.plugins=/var/lib/neo4j/plugins uncommented in the /etc/neo4j/neo4j.conf
The problem is that each time we run:
systemctl restart neo4j
It resets the neo4j.conf to the original configuration.