Parsing error importing ics file to calendar

[d-tamm]

Steps to reproduce

1. Click Calendar Settings.
2. Click Import Calendar
3. Choose the attached ics file

Expected behavior

Nextcloud should show a dialog where I can chose which calendar the file should be imported to.

Actual behaviour

I get the following to error messages:
No valid files found, aborting import
stefanie-2024-01-07.ics could not be parsed

Calendar app version

4.6.2

CalDAV-clients used

No response

Browser

Firefox 121.0

Client operating system

Windows 11

Server operating system

Docker linuxserver:nextcloud on Debian

Web server

Nginx

Database engine version

MariaDB

PHP engine version

None

Nextcloud version

28.0.1

Updated from an older installed version or fresh install

Fresh install

List of activated apps

No response

Nextcloud configuration

No response

Web server error log

No response

Log file

No response

Browser log

No response

Additional info

It seems to be row 36 which causes the parsing error:
TRIGGER;VALUE=DURATION;RELATED=START:P
According to https://icalendar.org/validator.html, the ics file is OK.
sample.ics.txt

[d-tamm]

BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
PRODID:-//SabreDAV//SabreDAV//EN
BEGIN:VTIMEZONE
TZID:Europe/Stockholm
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:19700329T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:19701025T030000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;VALUE=DATE:20110718
DTEND;VALUE=DATE:20110723
X-MICROSOFT-CDO-ALLDAYEVENT:TRUE
CLASS:PUBLIC
SUMMARY:0.5 Elternzeit
PRIORITY:5
TRANSP:OPAQUE
UID:032c8db7-5c58-4d3b-88fd-42e443a44ffc
STATUS:CONFIRMED
CREATED:20120227T203055Z
LAST-MODIFIED:20120227T203057Z
DTSTAMP:20131003T195443Z
BEGIN:VALARM
TRIGGER;VALUE=DURATION;RELATED=START:P
ACTION:DISPLAY
DESCRIPTION:0.5 Elternzeit
END:VALARM
END:VEVENT
END:VCALENDAR

[tcitworld]

According to https://icalendar.org/validator.html, the ics file is OK.

START:P looks suspicious. Could be "valid" as per the ICS spec, but definitely an odd period. PRODID says the file was produced by SabreDAV, is that correct?

[tcitworld]

Just found sabre-io/vobject#467 so the issue should be fixed in the backend.

Front-end it might be easier to add a repair step to change durations of P in PT0S than to fix it in ICAL.js

[tcitworld]

Does the data comes from Exchange/Outlook in your case?

[d-tamm]

The data is a part of an export I made yesterday from another Nextcloud instance. Since this event is quite old, I cannot say how it has been generated from the beginning.