[horde] Kronolith problem

[r.j.baart at prompt.nl]

Hi,

I want to connect with Thunderbird//Lightning to a horde webmail 
calender (ICS). Doing so I receive an error:

2017-07-08T18:12:05+02:00 EMERG: HORDE [kronolith] Allowed memory size 
of 134217728 bytes exhausted (tried to allocate 4194304 bytes) [pid 4968 
on line 558 of "/usr/share/php/Horde/Date.php"]

The calender will not synchronise. Normally I have no problems with the 
ics format. But if I change to caldav format the calender will synchronize.

Is this a bug or php-limit? Do I do anything wrong? Horde framework is 
up to date, server is Debian jessie, php version 5.6.30.

-- 

Cordialement,

R.J. Baart