No more calendar synchronization nextcloud 16.04 and thunderbird

Hello, everybody,
i have version 16.04. of the nextcloud. Unfortunately I noticed that the calendar is no longer synchronized to thunderbird.
The following Caldav - address is stored in Thunderbird.
Can anyone help me? I would be very grateful for a tip.

My Thunderbird Calendar sync address is slightly different:
https://cloud.example.tld/remote.php/dav/calendars/<user name>/personal/
It works just fine.

I’m using nextcloud 16.0.4 as I already wrote.
I have the same as you defined. I have them grayed out (I use two calendars) but both in thunderbird!

I too have the same link (, but mine is working.

When you right-click the calendar and go to properties, is the “Switch this calendar on” checkbox ticked? (Stupid question, I know, just starting at the beginning!)

Also, what Thunderbird version are you using? I’m on 60.8.0. My calendars are set to refresh every 30 minutes, and the three checkboxes below that setting are unchecked.

Did you change or upgrade anything before noticing the calendar stopped?

As a last resort, you could try creating a new calendar, call it something different, but use the old link. That will tell you whether it’s an issue with the link or if something happened to the Thunderbird calendar.

I also use Thunderbird version 60.8.0.
And set the checkbox “Activate this calendar”. But then it will be grayed out again.
I have no explanation for it. I am helpless.
Even if I define a new calendar. It is also grayed out this.

I have a similar problem:
No synchonisation onto an new account, but everything well on some old accounts at the the same NextCloud instance.

The joke is, actually. With version 15 of nextcloud it still worked.
Oh yes, on the mobil phone (android) the synchronization of the calendar works.
What was I wondering?
Maybe it’s the 2-factor authentication

Of course you cannot log in only with your password. That’s the reason of 2-factor authentication and why you can generate app-passwords :slight_smile:

So it may be that the nextcloud 16 has a bug regarding 2-factor authentication?
I enabled this in the nextcloud. I also use Thunderbird 68, with which I also use Calendar.
In the nextcloud I create a new app password under “Security”. But this password only lasted a maximum of 24 hours. Then I have to create a new one if I want to synchronize the calendars in Thunderbird.
I also fly out of the nextcloud every 3 minutes and have to log in again.
Does anyone have the same problem?

Does anyone found a solution? I have the same issue with my nextcloud and the thunderbird calendar synchronization. I also think it’s related to the 2-factor authentication because i can enter my username and password and that’s it. But for me, the second factor is missing?.

I also added a Google Calendar which is also based on 2 factor and there i have to enter - or let’s say i have the chance to use - the second factor before the calendar works.

So i found a solution. You have to click on “Setting” -> “Security” -> “Create new App password”. The account and selected password can be used to access e.g. the calendar app without 2-factor authentication.

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