The problem is likely with the Sheet itself - especially if the "View" test works, but the "Interact" tests fails. Tableau is likely executing the test just fine (you can check the admin "Load Time" dashboard to verify that the viz loads successfully), but TabJolt itself doesn't know how to parse the response FROM Tableau in this case.
I've normally seen this happen before with (generally complex) vizzes. In the short term, there's probably nothing that can be done except for you to simplify / play with the viz which is failing. About 60% of the time I can get a viz which causes this behavior to "start working" by re-arranging and/or removing some of the quick filter, putting less values IN the quick filters, making sure that the viz doesn't show many, many marks, and just simplifying it in general. The other 40% of the time I have to take the viz in question out of my workload, or ignore the errors.
It probably would be good to get a copy of this worksheet and some sample data.