Possible Solutions:
1. Make sure you remember to insert the code found at bottom after you save your setting changes.
2. Make sure you add slides orderly as in … top to bottom: (1, 2, 3, 5, ..etc) order. If you skip #1 or leave it blank (without image)for example, and went ahead and add image to #2,3,4 your slider will not show.
3. If all fails, deactivate plugin, update, and reactivate.
This was exactly I did while experiencing the same problem.