Cannot subscribe or import to ics calendar

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Steps to reproduce
1. Import ics file or insert ics url in subscription field
2.
3.

Expected behaviour
Calendar be added/subscribed

Actual behaviour
Import: Internal Server error 500
Subscription: note with fatal error in webcal-Proxy

Server configuration
Operating system: webhoster -> probably linux
Web server: webhoster
Database: MySQL
PHP version: 5.4
ownCloud version (see ownCloud admin page): 9.1.3
Updated from an older ownCloud or fresh install: fresh install
Special configuration (external storage, external authentication, reverse proxy, server-side-encryption): no

ownCloud log (data/owncloud.log)

nothing is logged

Integrity status for oC9+
Integrity failed because I added a person script for a manual OC update. But this script is not active.

[b]calendar sample[b]
The calendar works with Thunderbrid

BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//BRK//Pers Events//EN
METHOD:PUBLISH
X-LOTUS-CHARSET:UTF-8
X-WR-CALNAME:BRK
X-WR-CALDESC:BRK
CALSCALE:GREGORIAN
BEGIN:VTIMEZONE
TZID:Europe/Berlin
X-LIC-LOCATION:Europe/Berlin
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:19700329T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:19701025T030000	
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
UID:267@domain.de
SEQUENCE:0
STATUS:CONFIRMED
TRANSP:TRANSPARENT
DTSTART:20170113T180000
DTEND:20170113T193000
DTSTAMP:20170115T100348
SUMMARY:HvO Supervision
LOCATION: BRK  M?nchen
DESCRIPTION: Referent: Dr.med. S\nArt: HvO Supervision\nAnmerkung: 
CATEGORIES:myCategory
END:VEVENT