This error appears whenever the Create Agent is not installed or when the plug in needs to be updated or needs permissions.
If you click in the
Learn more button, it will show some usual fixes.
Check if the agent is running. You should see the icon in the taskbar and its color should be black or green, not grayed out. If it is grayed out, rick-click and select Run Agent. If you don't see the icon, open the agent by searching
If this is happening in school computers, it might be related to the app rights, please consult with the IT department to allow/install the Arduino Create Chrome app on all the devices. You may share the instructions available on this tutorial.