0|mm       | Whoops! There was an uncaught exception...
0|mm       | TypeError: Cannot read property 'fetchDepartures' of undefined
0|mm       |     at Class.fetchDepartures (/home/pi/MagicMirror/modules/MMM-PublicTransportHafas/node_helper.js:56:12)
0|mm       |     at Class.socketNotificationReceived (/home/pi/MagicMirror/modules/MMM-PublicTransportHafas/node_helper.js:21:14)
0|mm       |     at Socket. (/home/pi/MagicMirror/modules/node_modules/node_helper/index.js:113:11)
0|mm       |     at emitTwo (events.js:106:13)
0|mm       |     at Socket.emit (events.js:194:7)
0|mm       |     at /home/pi/MagicMirror/node_modules/socket.io/lib/socket.js:513:12
0|mm       |     at _combinedTickCallback (internal/process/next_tick.js:73:7)
0|mm       |     at process._tickCallback (internal/process/next_tick.js:104:9)
0|mm       | MagicMirror will not quit, but it might be a good idea to check why this happened. Maybe no internet connection?
0|mm       | If you think this really is an issue, please open an issue on GitHub: https://github.com/MichMich/MagicMirror/issues

sometimes there’s only 3 ERRORs, sometimes there’s more. They don’t show after the appear on (re)start.

		{
			module: "MMM-PublicTransportHafas",
			position: "bottom_left",

			config: {
				stationID: "xxx",						// Replace with your stationID!
				stationName: "xxx Bahnhof",				// Replace with your station name!

				direction: "yyy",						// Show only departures heading to this station. (A station ID.)
				ignoredLines: [],							// Which lines should be ignored? (comma-separated list of line names)
				excludedTransportationTypes: ["BuN"],		// Which transportation types should not be shown on the mirror? (comma-separated list of types) possible values: StN for tram, BuN for bus, s for suburban
				timeToStation: 10,							// How long do you need to walk to the next Station?
				timeInFuture: 190,

				showColoredLineSymbols: true,				// Want colored line symbols?
				useColorForRealtimeInfo: true,				// Want colored real time information (timeToStation, early)?
				showTableHeadersAsSymbols: true,			// Table Headers as symbols or text?
				maxUnreachableDepartures: 2,				// How many unreachable departures should be shown?
				maxReachableDepartures: 5,					// How many reachable departures should be shown?
				showOnlyLineNumbers: false					// Display only the line number instead of the complete name, i. e. "11" instead of "STR 11"
			}
		},

PS: stationID is correct, just marked for privacy