Hi I have the same problem on two different hosts, both use Debian GNU/Linux 11 with Apache HTTP Server 2.4.51. * one is a productive machine using Koha 21.05.02 * the other one is my demo installation using Koha 21.11.00 Both work as you would expect on the surface, but both show lots and lots of lines like the following in logfile "/var/log/apache2/error.log": [Mon Dec 06 22:48:51.598100 2021] [core:notice] [pid 3741] AH00052: child pid 4169 exit signal Segmentation fault (11) [Mon Dec 06 22:48:51.598225 2021] [core:notice] [pid 3741] AH00052: child pid 4170 exit signal Segmentation fault (11) [Mon Dec 06 22:48:51.598262 2021] [core:notice] [pid 3741] AH00052: child pid 4212 exit signal Segmentation fault (11) Even after hours of searching I couldn't find the reason for this behaviour, least of all the solution to it... Has anyone ever seen this before? Can anyone maybe confirm this on his own host with Debian 11 and Apache 2.4.51? Best wishes: Michael -- Geschäftsführer · Diplombibliothekar BBS, Informatiker eidg. Fachausweis Admin Kuhn GmbH · Pappelstrasse 20 · 4123 Allschwil · Schweiz T 0041 (0)61 261 55 61 · E mik@adminkuhn.ch · W www.adminkuhn.ch