Module stops with error message "userAgent must be a string"

[RolSch01]

Hi.
I just installed a clean new version of MagicMirror, added this module (from the greenkeeper/hafas-client-5.1.1 branch) modified the example configuration with my own station ID and started MM.
But the module crashes with the following message:

[17:46:00.564] [ERROR] TypeError: userAgent must be a string
at createClient (/home/pi/MagicMirror/modules/MMM-PublicTransportHafas/node_modules/hafas-client/index.js:31:9)
at new HafasFetcher (/home/pi/MagicMirror/modules/MMM-PublicTransportHafas/core/HafasFetcher.js:29:24)
at Class.createFetcher (/home/pi/MagicMirror/modules/MMM-PublicTransportHafas/node_helper.js:31:17)
at Class.socketNotificationReceived (/home/pi/MagicMirror/modules/MMM-PublicTransportHafas/node_helper.js:17:14)
at Socket. (/home/pi/MagicMirror/js/node_helper.js:113:11)
at Socket.emit (events.js:198:13)
at /home/pi/MagicMirror/node_modules/socket.io/lib/socket.js:528:12
at process._tickCallback (internal/process/next_tick.js:61:11)
^Cevents.js:174
throw er; // Unhandled 'error' event
^
A can find the reason. The code seems to be ok. (hands over a static string to the method)

My configuration:

{
module: "MMM-PublicTransportHafas",
position: "bottom_right",
config: {
stationID: "00903736", // Replace with your stationID!
stationName: "Holzwickede Bahnhof", // Replace with your station name
direction: "", // Show only departures heading to this station. (A station ID.)
ignoredLines: [], // Which lines should be ignored? (comma-separated list of line names)
excludedTransportationTypes: ["bus"], // (comma-separated list of types) possible values: StN for tram, BuN for bus, s for suburban
timeToStation: 8, // How long do you need to walk to the next Station?
timeInFuture: 60,
showColoredLineSymbols: true, // Want colored line symbols?
useColorForRealtimeInfo: true, // Want colored real time information (timeToStation, early)?
showTableHeadersAsSymbols: true, // Table Headers as symbols or text?
maxUnreachableDepartures: 0, // How many unreachable departures should be shown?
maxReachableDepartures: 7, // How many reachable departures should be shown?
customLineStyles: "", // Prefix for the name of the custom css file. ex: Leipzig-lines.css (case sensitive)
showOnlyLineNumbers: false // Display only the line number instead of the complete name, i. e. "11" instead of "STR 11"
}
},

I did the following:
git clone ....
git checkout greenkeeper/hafas-client-5.1.1
npm install

Master didn't compile with version conflicts.

When i disable the module MM starts and runs normally.
Any idea?
Thanks in advance.

[RolSch01]

I really don't know what the problem was.
Just deleted and reinstalled the module. Didn't change anything else.
Now it runs like a charm.

Thanks for coding it.

[derhuerst]

Author of hafas-client, the library used by MMM-PublicTransportHafas, here.

hafas-client@5 has breaking changes over the currently used hafas-client@2. This means that you cannot upgrade from hafas-client@2 to hafas-client@5 without adapting the MMM-PublicTransportHafas code. This is why it complains about a missing userAgent argument.

The greenkeeper/hafas-client-5.1.1 branch has been created by a bot, which did obviously not adapt the MMM-PublicTransportHafas code to hafas-client@5. For a German discussion on upgrading hafas-client, check #67. This repo doesn't seem to be maintained though.