What is causing the save to repository task to suspend? Are there mandatory fields in the template that don't have data in them? 

I would ease the restriction at the template level (make the fields not required or remove the field validation that is preventing the form from saving), retry the instance so it saves to the repository, then put the restriction back in place. You can update the field values from the web client after the fact. 

If you are on the latest 10.4.3, you could use the new skip feature to try and fix this as well. One way to do this would be to

1. Update the process to have a user task after the stuck save to repository task. Make sure the task is assigned to you and has a form with all the variables you wish to fix. 
2. Add a copy of the save to repository task after the new user task
3. Save the process
4. Go to monitor and find the suspended instance and skip the stuck save to repository task
5. This will send that instance to the user task where you can go fix the variables
6. Submit the form with the updated variables and the second save to repository should run successfully
7. Go back to the process and remove the added steps