Hi @dislu_do,
Thank you for reaching out to us. Essential Grid is a bundled plugin that comes with X/Pro and for all the bundled plugins which you have installed, there is no need to activate or register it. Even without registering or activating the plugins, you should be able to use all the features of the plugin. We will be the ones who will provide you with updates. If there are any plugin updates, you can see it in your dashboard (Dashboard > Updates) and will be able to update to the latest versions provided that you have validated the theme. Of course you can always proceed to update it because I am sure that you already validated your theme.
You can safely dismiss the notice in your dashboard. Hope this helps!