edit ~/MagicMirror/js/check_config.js

change line 57 to look like this

		const messages = linter.verify(data);

change line 66 to look like this

	//		throw new Error("Wrong syntax in config file!");

i would guess that you pasted the ModuleScheduler module block in the wrong place, after the end for the modules ;[] array closure

] //< — what is this?
}, // < - what is this?
{
module: “MMM-ModuleScheduler”

]; // < – what is ‘;’ this?

{
			module: "newsfeed",
			position: "bottom_bar",
			config: {
				feeds: [
					{
						title: "BBC UK",
						url: "https://feeds.bbci.co.uk/news/rss.xml?edition=uk"
					}
				],
				showSourceTitle: true,
				 showPublishDate: true,
				broadcastNewsFeeds: true, 
				broadcastNewsUpdates: true
			}
		},
	]  // < --- this?
},  // < --- this?
{
        module: "MMM-ModuleScheduler",
        config: {
            notification_schedule: [
                // TURN THE MONITOR/SCREEN ON AT 07:30 EVERY DAY
                {notification: 'REMOTE_ACTION', schedule: '20 15 * * *', payload: {action: "MONITORON"}},
                // TURN THE MONITOR/SCREEN OFF AT 22:30 EVERY  DAY
                {notification: 'REMOTE_ACTION', schedule: '25 15 * * *', payload: {action: "MONITOROFF"}},
                // RESTART THE MAGICMIRROR PROCESS AT 2am EVERY SUNDAY
                {notification: 'REMOTE_ACTION', schedule: '0 2 * * SUN', payload: {action: "RESTART"}}
            ]
        }
    };   //< --- ';' this