I've set up the Action Plans app, (https://appexchange.salesforce.com/listingDetail?listingId=a0N30000003HcINEA0)

And following the documentation.

First up it would seem the documentation for setting up a Custom Object against the action plans is a bit out of date, but I can work around the slight differences there I believe.

However, I'm getting the following error when running tests. 

Class.ActionPlansBatchBuilderTest.runBatchException: line 316, column 1.

I thought this was down to some changes I had made being incorrect so I ran all tests on production. They passed.

I then refreshed the Sandbox, and once ready ran the tests there. And this error comes up immediately. 

Has anyone else encountered this problem with Action Plans, and found a work around?