Forum der Gemeinschaft Thunderbird

Recently the reminders from my calendar in Thunderbird have failed to show, as if there is a setting that has been turned off. How can I turn them back on again? Thank you. Update: I found for half a day the reminders returned, but they disappeared again. Does anybody have any idea as to what is going on?

Cannot dismiss reminder or set the snooze. Get the following:

Status Code: 2147500037, The request cannot be processed.

An error occurred when writing to the calendar charles.novak@gmail.com! Please see below for more information.

Server Replied with 400 If you're seeing this message after snoozing or dismissing a reminder and this is for a calendar you do not want to add or edit events for, you can mark this calendar as read-only to avoid such experience in future. To do so, get to the calendar properties by right-clicking on this calendar in the list in the calendar or task view.

Hi,

Does anyone have an issue with Thunderbird not displaying Teams invites correctly. Would be useful to have a solution.

Attached a screen shot and redacted the some of it for obvious reasons.

Thanks in advance

R

Meine Kalendererinnerungen werden nicht mehr ausgeführt seit dem letzten Update. Auch neue Einträge mit Erinnerungsfunktion werden nicht ausgeführt. Das alles passiert erst seit dem letzten Update auf Version 140.2.0esr (64-Bit) auf einem Windows 11 64bit. Im Fehlerbehebungsmodus geht es jedoch.

For some reason, when I add a new event to one of my Thunderbird calendars, it shows up an hour later when I reopen Thunderbird.

For example: 1) create a new event at 9am and sync 2) close Thunderbird 3) reopen Thunderbird 4) event is at 10am

The native iOS calendar app still shows it at 9am, as does the web interface for the calendar provider (Hetzner webhosting). Once the times are shifted, they stay consistent, but the issue happens again if I try to edit the time an hour back.

I have verified that I am using the New York timezone everywhere.

I have an Outlook calendar in Thunderbird as well (using the Owl plugin), but it doesn't seem to have this issue.

Any thoughts? Thank you!

Please reverse the REMINDER PANEL column order to Improve Usability:

NOW: "Event description" (_BIG_ whitespace) "Event Date Time"

SUGGEST: "Event Date Time" (small whitespace) "Event description"

WHY:

"Event Date Time" is fixed-length (short) "Event description" is variable-length (longer)

The suggested column order brings the "Event Date Time" closer to the "Event description" and INCREASES READABILITY.

Thank you, -Mike Ramey

Hello, I probably desactivated by mistake the reminder pop up window for event and tasks in the agenda. So that i do not get any warning 1 day before the event as specified in the creation of the event. How can i re-instate this alarm ? Tks brds

I have just had a scam calendar entry added without me accepting the invite or an email requesting it.

The entry has clickable links - obviously scam/spam

How could that happen?

Using Tunderbird 128.8.1esr (64-Bit) on Windows 11 Since today, my externally bound-in calendars (not google) stopped working. When i start Thunderbird, the calendars load as usual and all appointments show up, but after a few seconds, all calendars disappear. I can neither add new appointments nor see the current ones.

I am using no addons, so I guess the calendar app is lightning

Additionally, this seems to be not the first time, that a thunderbird update causes problems with the calendar (that is delivered within the same software-suite!) as i have seen multiple versions of the same post with different build numbers, all with the "solution" to reinstall. Thit can't be the goal of QC.

Hello. I need to move >1000 calendar events from calendar "medical" to my "home" calendar and (at one go) assign the category "medical":

from [calendar: "medical" / category: none] --> to [calendar: "home" / category: "medical"]

How can I do this ?

I really hate typing so I welcome every oportunity to import data, text, appointments etc. My problem is with recent downloads from MyChart (Epic Systems) the add to your calendar option for appointments downloads an ICS file. I can add the ICS file but the right click edit option is disabled. I have noticed that "Provider for Google Calendar" an extension is disabled and I cannot enable it. It is incompatable with TB141. I am runnining Windows 10. I cannot find the FAQ site.

Up until this point the extension p[erated flawlessly. It was updated on July1 within a few days when I can document the problem begining.

Environment:

• Ubuntu 22.04
• Thunderbird 128.12.0esr

Background:

Yesterday (7/25/2025) Ubuntu ran an auto-update and appears to have updated tbird. At the time this did not affect tbird as it was up and running with the old version of code.

Today (7/26/2025), upon starting tbird and clicking on the Calendar tab tbird goes into 100% cpu utilization.

This issue appears to be related to changes in how recurring events are now listed under Calendar as individual events. For events with no ending date this new 'feature' now generates entries for the next 100 years (eg, 26 July 2025 - 26 July 2125).

Steps I've performed in an attempt to address the 100% cpu utilization issue:

1. shutdown tbird, renamed calendar-data/local.sqlite (effectively erase all calendar events), start tbird, click on Calendar tab ... little/no cpu utilization; great, cpu utilization is back to normal but my calendar is gone
2. shutdown tbird, put calendar-data/local/sqlite back in place, started tbird, do NOT click on Calendar tab, [menu] Events and Tasks -> Export -> saved all calendar events to an external *.ics file; shutdown tbird, renamed calendar-data/local.sqlite (effectively erase all calendar events), start tbird, [menu] events and Tasks -> "Import" -> import all (202) calendar events from the *.ics file; tbird goes into 100% cpu utilization for about 5 minutes and then becomes unresponsive
3. repeat of previous bullet up until the Import step; at this point I imported a single recurring event (happens once a month with no end date); tbird successfully imported the 1 recurring event and upon clicking on the Calendar tab ... I'm presented with 1200 individual event entries -> once a month up through July 2125
4. upon creating 1 event that repeats on a daily basis, tbird goes into 100% cpu utilization for a few seconds while it generates more than 36,500 individual events (up through July 2125) under the Calendar tab

At this point it appears (to me) that tbird's 100% cpu utilization and unusable UI is related to tbird having a hard time managing my 202 calendar events (most of which are recurring events - mostly monthly but there are several daily and weekly events, too).

This latest update of tbird is unusable!

Please rollback this behavior of expanding recurring events into individual events, or at a minimum give us a setting that keeps tbird from expanding recurring events into individual entries under the Calendar tab.

In the meantime, since tbird is running in a virtual machine, I'm rolling back to a previous snapshot and disabling Ubuntu's automatic updates of tbird software.

I am trying to import a ics file into thunderbird. If I specify a local calendar as the destination calendar, the import works. However, if I specify a caldav-connected calendar as the destination, the import starts but never completes, and I always see an import status of 0%. I have tried importing into calendars from different caldav providers, but in all cases, the import fails. I would greatly appreciate your feedback. For me, this import is a convenient way to semi-automatically populate a web calendar.

When trying to edit the Description of a Calendar Event the description window only shows part of the first line. I am unable to scroll or resize the text box. Windows 11 64 bit, Thunderbird 1.28 and Thunderbird Eclipse 140.0.1 - 64 bit

The reminders window that normally starts up when Thunderbird opens no longer appears. To be clear it's the window that shows my daily appointments in a separate window. Thanks

I got a new PC with Windows 11. I installed Thunderbird 136.0.1 , activated the private calendar, and entered events there. For events with a reminder that have a specific duration (e.g., Wednesday from 10 AM to 11 AM), I receive notifications. However, when I create a full-day event and want to be reminded, for example, 1 day before, I don't receive any notification. Additionally, events with a reminder are not shown in bold in the calendar overview (whether they have a specific duration or are all-day events). Can you please help me?

Hi everyone.

Hoping someone may be able to help. I see that other users are able to fully highlight the events in calendar. I seem to be only able to highlight 2/3's (see image)

Thanks in advance