[horde] redis cache server

[Ruud Baart]

Hi,

Question about redis on a debian system in combination with Horde 5. 
Environment Horde 5.2.22, php 7.4, nginx, debian bullseye server.

I would like to replace the memcache server by a redis server. In fact 
not very difficult.

Redis server works fine and several wordpress websites were changed form 
memcache to redis without a problem. However if I change "the 
distributed hastable" in the horde configuration I get an error:

024-06-02T11:17:54+02:00 EMERG: HORDE Error: Class 'Predis\Client' not 
found in /usr/share/php/Horde/Core/Factory/HashTable.php:107

and horde stops working. I can't find any useful information about this 
error. Can someone give me a hint?