There might occur some difficulties using WordPress Slider plugin with the newest WordPress 5.6 version. Our developers are working to fix the compatibility with WordPress 5.6. Meanwhile, we recommend staying on the previous version of WordPress or downgrade WordPress if you have already updated it. You can try using the following plugin to downgrade WordPress https://wordpress.org/plugins/wp-downgrade/ or in any other convenient way. We strongly recommend backup your site before any up- or downgrade.
We are terribly sorry for the temporary inconvenience.