several errors

I purchased a Learning Management System from Edulms called Education and it came with a bunch of demo-data files including the sliders with the included revolutionary slider. After using the revolutionary slider import option, I navigated to the folder where the sliders were being stored and installed 5 of the ones included. For the life of me, I can’t get them to show up. I keep getting Revolution Slider Error: Slider with ID: 20 Not Found and if I change to a different demo data theme, the number changes but the error stays. You can see the error at my site https://www.myielts.ca/

I don’t have any idea whats going on and I did contact the publisher but apparently, he only answers occasionally. I am really wanting to get the layout that I purchased seen here https://themeforest.net/item/edulms-wp-learning-management-system-theme/9443786 which is completely different from what I am looking at.

Any ideas on how to trouble shoot my issue?