Update: solved the problem by using your solution here: https://forum.magicmirror.builders/topic/13770/2-13-calendar-fix-for-office-365-users but I don’t have a Office 365-account.
Thanks for the solution!!

Ok, so maybe I had something running in the background that I couldn’t see. When I ran npm start dev I got this error instead:

[2020-12-30 22:53:03.906] [ERROR]  Whoops! There was an uncaught exception...
[2020-12-30 22:53:03.908] [ERROR]  TypeError: Cannot read property 'iana' of undefined
    at getIanaTZFromMS (/home/pi/MagicMirror/node_modules/node-ical/ical.js:108:30)
    at /home/pi/MagicMirror/node_modules/node-ical/ical.js:175:23
    at Object.DTSTART (/home/pi/MagicMirror/node_modules/node-ical/ical.js:457:32)
    at Object.handleObject (/home/pi/MagicMirror/node_modules/node-ical/ical.js:483:39)
    at Object.parseLines (/home/pi/MagicMirror/node_modules/node-ical/ical.js:534:18)
    at Object.parseICS (/home/pi/MagicMirror/node_modules/node-ical/ical.js:590:18)
    at Object.sync.parseICS (/home/pi/MagicMirror/node_modules/node-ical/node-ical.js:190:15)
    at Object.autodetect.parseICS (/home/pi/MagicMirror/node_modules/node-ical/node-ical.js:221:17)
    at Request._callback (/home/pi/MagicMirror/modules/default/calendar/calendarfetcher.js:79:22)
    at Request.self.callback (/home/pi/MagicMirror/node_modules/request/request.js:185:22)

@sdetweil thanks! but it only seems like I have one instance running because now nothing is running.

Hi!
I have problem with one of my calendars that wont show events. The problem started when updating to v2.13.0 and the calendar module caused the mirror to only show a blank screen. I solved it by outcomment the module and haven’t had time to dig into it for months until now.
The problem back then I think was that I had changed the calendar names, so the url’s were wrong, so now I have solved it to show two calendars, but cannot see the last calendar’s event. I have tripple checked the ical-address, so that’s not the problem now. I have also gone through this link: https://github.com/MichMich/MagicMirror/issues/839 and tried to see if I got the same problem by run npm start dev but I wont get the same error message. This is my error message:

> magicmirror@2.13.0 start /home/pi/MagicMirror
> DISPLAY="${DISPLAY:=:0}" ./node_modules/.bin/electron js/electron.js "dev"

/home/pi/MagicMirror/node_modules/electron/dist/electron: /lib/arm-linux-gnueabihf/libdbus-1.so.3: no version information available (required by /home/pi/MagicMirror/node_modules/electron/dist/electron)
/home/pi/MagicMirror/node_modules/electron/dist/electron: /lib/arm-linux-gnueabihf/libdbus-1.so.3: no version information available (required by /home/pi/MagicMirror/node_modules/electron/dist/electron)
[2020-12-30 22:08:23.415] [LOG]    Starting MagicMirror: v2.13.0
[2020-12-30 22:08:23.433] [LOG]    Loading config ...
[2020-12-30 22:08:23.447] [LOG]    Loading module helpers ...
[2020-12-30 22:08:23.451] [LOG]    No helper found for module: alert.
[2020-12-30 22:08:23.556] [LOG]    Initializing new module helper ...
[2020-12-30 22:08:23.558] [LOG]    Module helper loaded: updatenotification
[2020-12-30 22:08:23.564] [LOG]    Initializing new module helper ...
[2020-12-30 22:08:23.567] [LOG]    Module helper loaded: mmm-systemtemperature
[2020-12-30 22:08:23.570] [LOG]    No helper found for module: clock.
[2020-12-30 22:08:24.566] [LOG]    Initializing new module helper ...
[2020-12-30 22:08:24.569] [LOG]    Module helper loaded: calendar
[2020-12-30 22:08:24.677] [LOG]    Initializing new module helper ...
[2020-12-30 22:08:24.678] [LOG]    Module helper loaded: MMM-YrThen
[2020-12-30 22:08:25.787] [LOG]    Initializing new module helper ...
[2020-12-30 22:08:25.789] [LOG]    Module helper loaded: mmm-weatherchart
[2020-12-30 22:08:25.844] [LOG]    Initializing new module helper ...
[2020-12-30 22:08:25.845] [LOG]    Module helper loaded: newsfeed
[2020-12-30 22:08:25.846] [LOG]    All module helpers loaded.
[2020-12-30 22:08:26.086] [LOG]    Starting server on port 8080 ...
[2020-12-30 22:08:26.114] [LOG]    Server started ...
[2020-12-30 22:08:26.116] [LOG]    Connecting socket for: updatenotification
[2020-12-30 22:08:26.118] [LOG]    Connecting socket for: mmm-systemtemperature
[2020-12-30 22:08:26.119] [LOG]    Starting node helper: mmm-systemtemperature
[2020-12-30 22:08:26.120] [LOG]    Connecting socket for: calendar
[2020-12-30 22:08:26.121] [LOG]    Starting node helper for: calendar
[2020-12-30 22:08:26.122] [LOG]    Connecting socket for: MMM-YrThen
[2020-12-30 22:08:26.124] [LOG]    MMM-YrThen 12/30/2020 10:08:26 PM: Starting helper for MMM-YrThen
[2020-12-30 22:08:26.125] [LOG]    Connecting socket for: mmm-weatherchart
[2020-12-30 22:08:26.126] [LOG]    Starting node helper: mmm-weatherchart
[2020-12-30 22:08:26.129] [LOG]    Connecting socket for: newsfeed
[2020-12-30 22:08:26.131] [LOG]    Starting node helper for: newsfeed
[2020-12-30 22:08:26.133] [LOG]    Sockets connected & modules started ...
Fontconfig warning: "/etc/fonts/fonts.conf", line 86: unknown element "blank"
[2020-12-30 22:08:26.336] [ERROR]  Whoops! There was an uncaught exception...
[2020-12-30 22:08:26.341] [ERROR]  Error: listen EADDRINUSE: address already in use 127.0.0.1:8080
    at Server.setupListenHandle [as _listen2] (net.js:1226:14)
    at listenInCluster (net.js:1274:12)
    at GetAddrInfoReqWrap.doListen [as callback] (net.js:1413:7)
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:65:10) {
  code: 'EADDRINUSE',
  errno: 'EADDRINUSE',
  syscall: 'listen',
  address: '127.0.0.1',
  port: 8080
}
[2020-12-30 22:08:26.363] [ERROR]  MagicMirror will not quit, but it might be a good idea to check why this happened. Maybe no internet connection?
[2020-12-30 22:08:26.366] [ERROR]  If you think this really is an issue, please open an issue on GitHub: https://github.com/MichMich/MagicMirror/issues
[2020-12-30 22:08:26.380] [LOG]    Launching application.

I have also checked the ical.js solution, but I don’t know how to solve it, because I only have a folder with that name and cannot create a file.
I don’t have a lot of programming knowledges so please kind answers

@evroom got an error on the egrep command:

pi@raspberrypi:~ $ cat /proc/device-tree/model
Raspberry Pi 3 Model B Rev 1.2pi@raspberrypi:~ $ lsb_release -a
No LSB modules are available.
Distributor ID: Raspbian
Description:    Raspbian GNU/Linux 8.0 (jessie)
Release:        8.0
Codename:       jessie
pi@raspberrypi:~ $ npm --version
5.6.0
pi@raspberrypi:~ $ node --version
v9.11.2
pi@raspberrypi:~ $ pm2 --version
3.5.1
pi@raspberrypi:~ $ cat /boot/config.txt | egrep -v '^$|^#|^['
grep: Invalid regular expression

@evroom actually no errors like I got before…

PM2        | 2019-08-29T21:46:00: PM2 log: pid=1331 msg=failed to kill - retrying in 100ms
PM2        | 2019-08-29T21:46:00: PM2 log: App [mm:0] exited with code [0] via signal [SIGINT]
PM2        | 2019-08-29T21:46:00: PM2 log: pid=1331 msg=process killed
PM2        | 2019-08-29T21:46:00: PM2 log: App [mm:0] starting in -fork mode-
PM2        | 2019-08-29T21:46:00: PM2 log: App [mm:0] online

/home/pi/.pm2/logs/mm-out.log last 100 lines:
0|mm       | Shutting down server...
0|mm       | Stopping module helper: updatenotification
0|mm       | Stopping module helper: mmm-systemtemperature
0|mm       |
0|mm       | > magicmirror@2.8.0 start /home/pi/MagicMirror
0|mm       | > sh run-start.sh
0|mm       |
0|mm       | Starting MagicMirror: v2.8.0
0|mm       | Loading config ...
0|mm       | Loading module helpers ...
0|mm       | No helper found for module: alert.
0|mm       | Initializing new module helper ...
0|mm       | Module helper loaded: updatenotification
0|mm       | Initializing new module helper ...
0|mm       | Module helper loaded: mmm-systemtemperature
0|mm       | No helper found for module: clock.
0|mm       | Initializing new module helper ...
0|mm       | Module helper loaded: calendar
0|mm       | Initializing new module helper ...
0|mm       | Module helper loaded: MMM-YrThen
0|mm       | Initializing new module helper ...
0|mm       | Module helper loaded: mmm-weatherchart
0|mm       | Initializing new module helper ...
0|mm       | Module helper loaded: newsfeed
0|mm       | All module helpers loaded.
0|mm       | Starting server on port 8080 ...
0|mm       | Server started ...
0|mm       | Connecting socket for: updatenotification
0|mm       | Connecting socket for: mmm-systemtemperature
0|mm       | Starting node helper: mmm-systemtemperature
0|mm       | Connecting socket for: calendar
0|mm       | Starting node helper for: calendar
0|mm       | Connecting socket for: MMM-YrThen
0|mm       | MMM-YrThen 8/29/2019 9:46:08 PM: Starting helper for MMM-YrThen
0|mm       | Connecting socket for: mmm-weatherchart
0|mm       | Starting node helper: mmm-weatherchart
0|mm       | Connecting socket for: newsfeed
0|mm       | Starting module: newsfeed
0|mm       | Sockets connected & modules started ...
0|mm       | Launching application.

/home/pi/.pm2/logs/mm-error.log last 100 lines:
0|mm       | /home/pi/MagicMirror/node_modules/electron/dist/electron: /lib/arm-linux-gnueabihf/libdbus-1.so.3: no version information available (required by /home/pi/MagicMirror/node_modules/electron/dist/electron)
0|mm       | /home/pi/MagicMirror/node_modules/electron/dist/electron: /lib/arm-linux-gnueabihf/libdbus-1.so.3: no version information available (required by /home/pi/MagicMirror/node_modules/electron/dist/electron)
0|mm       | (node:2465) [DEP0025] DeprecationWarning: sys is deprecated. Use util instead.
0|mm       | /proc/self/exe: /lib/arm-linux-gnueabihf/libdbus-1.so.3: no version information available (required by /proc/self/exe)
0|mm       | ATTENTION: default value of option force_s3tc_enable overridden by environment.

I really appreciate you want to look into my errors, I’m not too good on this

And of course it didn’t work now when I tried to switch back to default calendar module and then back to the other calendar module…

@evroom I sat right now and installed a new calendar module and suddenly the mmm-weatherchart started working…

Did the $ pm2 logs --lines 100 and got a lot of errors, but I guess because everything’s working fine so don’t have to bother right now?!

@sdetweil Thanks! This worked for me as it doesn’t kill it anymore. Hope for a quick fix. Can I follow the process somewhere?

Just to be clear, I’m a girl…
The module worked as a charm before the update. So you think I should just skip the apostrophe on the updateInterval and hideBorder?