Unable to save job config after updating to the latest version of Jenkins. Steps to reproduce.

1. Push a job to Jenkins using JJB
2. Jenkins -> login -> Find the job -> configure
3. Change any of the job config settings
4. Save changes in the job config.
5. Returns the below error

net.sf.json.JSONException: JSONObject["com-sonyericsson-hudson-plugins-gerrit-trigger-hudsontrigger-GerritTrigger"] is not a JSONObject.
    at net.sf.json.JSONObject.getJSONObject(JSONObject.java:2006)
...    at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:383)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:882)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1036)