[kronolith] Calendar access with Thunderbid Lightning works only via ICS file

[Ferdinand Gruber]

With Thunderbird Lighning I only can display my Horde Kronolith calendar 
via an ICS:

ICS:
Using this address I can see my Horde Kronolith calendar in Thunderbird 
Lightning:
https://myserver.xx/horde/rpc.php/kronolith/username/fkDvuFjllQNJI2hBLZh6_A3.ics

CalDAV
Using this address I dont'see anything in Thunderbid Lightning:
https://myserver.xx/horde/rpc.php/kronolith/username/fkDvuFjllQNJI2hBLZh6_A3.ics

In the error console of Thunderbird I get 2 error messages:

    Warning: CalDAV: Fatal Error parsing etags for Kronolith_plain
    Quelldatei:
file:///home/username/.thunderbird/w5gv2ckr.default/extensions/%7Be2fda1a4-762b-4020-b5ad-a41df1933103%7D/calendar-js/calDavRequestHandlers.js 

    Line: 177

    Error: NS_ERROR_UNEXPECTED: Component returned failure code:
    0x8000ffff (NS_ERROR_UNEXPECTED) [nsISAXXMLReader.onDataAvailable]
    Quelldatei: resource://calendar/modules/calUtils.jsm ->
file:///home/username/.thunderbird/w5gv2ckr.default/extensions/%7Be2fda1a4-762b-4020-b5ad-a41df1933103%7D/calendar-js/calDavRequestHandlers.js 

    Line: 168

Now I tried wireshark to capture the http traffic. I can see a lot of 
lines with many ICS filenames. At the end of the trasmission it seems 
suddenly to stop.

Here are the last two records. I inserted a line break so it is easyer 
to read:

<d:response><d:href>/horde/rpc.php/calendars/username/calendar:fkDvuFjllQNJI2hBLZh6_A3/NlWPQRaEU6AqZaI-nDnmug1.ics</d:href><d:propstat><d:prop><d:getcontenttype>text/calendar; 
charset=utf-8</d:getcontenttype><d:resourcetype/><d:getetag>"72ea6a20a6e7b9044e0e0848f4a04f36"</d:getetag></d:prop><d:status>HTTP/1.1 
200 OK</d:status></d:propstat></d:response>

<d:response><d:href>/horde/rpc.php/calendars/username/calendar:fkDvuFjllQNJI2hBLZh6_A3/xpabAjnZMHboxyXmngYcfw9.ics</d:href><d:propstat><d:prop><d:getcontenttype>text/calendar; 
charset=utf-8</d:getcontenttype><d:resourcetype/><d:getetag>"c69adc113091ae2f17061f3642dbe884"</d:getetag></d:prop><d:status>HTTP/1.1 
200 OK</d:status></d:propstat></d:

System Info:
Server: Horde Groupware 5.2.10
OS: openSUSE 13.2

Client: Lightning in Thunderbird 38.2.0
OS openSUSE 13.2

I think that the CalDAV access would be faster then the ICS access.
Therfore I would like to get it work.

Please help

-- 
Greetings from Austria
Ferdinand Gruber