crash caused by mail with calendar request

[f-zappa]

I've been using this container for some days. Today for the first time I received a mail with a calendar request which caused z-push to crash. Only workaround was to move the mail out of the inbox with an imap client.

I added the line
define('IMAP_MEETING_USE_CALDAV', false);
to the imap.php (and recreated the container), but this didn't help.

I only want to sync mails with z-push, how can I make it ignore calendar requests and just deliver them as normal mails to the client?

Regards, Uli

19/08/2021 10:09:31 [ 309] [ERROR] [mail@example] LoopDetection->ProcessLoopDetectionPreviousConnectionFailed(): Command 'Sync' at 19/08/2021 10:07:35 with pid '57' terminated unexpectedly or is still running.
19/08/2021 10:09:31 [ 309] [ERROR] [mail@example] Please check your logs for this PID and errors like PHP-Fatals or Apache segmentation faults and report your results to the Z-Push dev team.
19/08/2021 10:09:32 [ 309] [WARN] [mail@example] Mobile loop detected! Messages sent to the mobile will be restricted to 1 items in order to identify the conflict
19/08/2021 10:09:32 [ 309] [WARN] [mail@example] /opt/zpush/include/iCalendar.php:49 require_once(XMLElement.php): failed to open stream: No such file or directory (2)
19/08/2021 10:09:32 [ 309] [FATAL] [mail@example] Fatal error: /opt/zpush/include/iCalendar.php:49 - require_once(): Failed opening required 'XMLElement.php' (include_path='.:/usr/local/lib/php:/usr/share/awl/inc') (64)