Random Rise360 module error- JSON Loader httpStatus: 500

We republished 12 of our Videos using Rise360 (originally Storyline) and have started to get random "JSON Loader httpStatus: 500" lockups  - a total of 20 course attempts. 

14 learners out of 250 assigned have been affected.

The error appears after the following end-of-course sequence:

1 - Video Completes, then 

2 - Continue button activates > learner selects the Continue Button

3 - Then the Exit Button activates, learner selects the Exit Button

4 - Learner has to then Select a window exit button - This is where the errors starts to appear. The LMS is not recording the completed status. We  have to admin complete these modules for the learner.

The error is happening on both PCs and Tablets equally.

I have uploaded to SCORMcloud and the manifest file comes back with no errors. All major browsers are involved. 4 of the Modules actually cleared themselves and changed the course status to completed after an initial error.

In sensing I'm going to learn how to use the debugging tool. 

Any ideas?