Comment 67 for bug 1846423

I'm worried the fix is not enough. I'm still having errors both in version 78.12.0 and 91.0b1, Linux & Windows:

CalDAV: Unexpected status modifying item to MyCalendar: 405
BEGIN:VCALENDAR
PRODID:-//Mozilla.org/NONSGML Mozilla Calendar V1.1//EN
VERSION:2.0
BEGIN:VEVENT
CREATED:20210630T085146Z
LAST-MODIFIED:20210717T090432Z
DTSTAMP:20210717T090432Z
UID:9c70b2b8-3019-471a-9a86-4e94c11b600b
SUMMARY:My event
X-MOZ-LASTACK:20210717T090432Z
DTSTART;VALUE=DATE:20210717
DTEND;VALUE=DATE:20210719
TRANSP:TRANSPARENT
X-MOZ-GENERATION:1
BEGIN:VALARM
ACTION:DISPLAY
TRIGGER;VALUE=DURATION:-PT15M
DESCRIPTION:Description par défaut Mozilla
X-LIC-ERROR;X-LIC-ERRORTYPE=PARAMETER-VALUE-PARSE-ERROR:Got a VALUE parame ter with an illegal type for property: VALUE=DURATION
END:VALARM
END:VEVENT
END:VCALENDAR

So maybe my patch is not enough? Any other returns?