Null pointer exception when loading into OrientDB from Oracle

Question

I have installed OrientDB V 2.1.11 on a Mac - El Capitan. I am following the instructions as per the OrientDB documentation. http://orientdb.com/docs/last/Import-from-DBMS.html When I run the oetl.sh I get a null pointer exception. I assume it is connecting to the Oracle instance. Json config:

{
  "config": {
    "log": "error"
  },
  "extractor" : {
    "jdbc": { "driver": "oracle.jdbc.OracleDriver",
              "url": "jdbc:oracle:thin:@<dbUrl>:1521:<dbSid>",
              "userName": "username",
              "userPassword": "password",
              "query": "select sold_to_party_nbr from customer" }
  },
  "transformers" : [
   { "vertex": { "class": "Company"} }
  ],
  "loader" : {
    "orientdb": {
      "dbURL": "plocal:../databases/BetterDemo",
      "dbUser": "admin",
      "dbPassword": "admin",
      "dbAutoCreate": true
    }
  }
}

Error:

sharon.oconnor$ ./oetl.sh ../loadFromOracle.json 
OrientDB etl v.2.1.11 (build UNKNOWN@rddb5c0b4761473ae9549c3ac94871ab56ef5af2c; 2016-02-15 10:49:20+0000) www.orientdb.com
Exception in thread "main" java.lang.NullPointerException
    at com.orientechnologies.orient.etl.transformer.OVertexTransformer.begin(OVertexTransformer.java:53)
    at com.orientechnologies.orient.etl.OETLPipeline.begin(OETLPipeline.java:72)
    at com.orientechnologies.orient.etl.OETLProcessor.executeSequentially(OETLProcessor.java:465)
    at com.orientechnologies.orient.etl.OETLProcessor.execute(OETLProcessor.java:269)
    at com.orientechnologies.orient.etl.OETLProcessor.main(OETLProcessor.java:116)

The data in Oracle looks like this:

0000281305
0000281362
0000281378
0000281381
0000281519
0000281524
0000281563
0000281566
0000281579
0000281582
0000281623
0000281633

I have created a Company class with a sold_to_party_nbr string property in the BetterDemo database.

How can I degbug further to figure out what is wrong?