The Server have this Error:

PHP Startup: Unable to load dynamic library 'memcached.so' (tried: /usr/lib/php/20190902/memcached.so (/usr/lib/php/20190902/memcached.so: undefined symbol: zend_wrong_parameter_error), /usr/lib/php/20190902/memcached.so.so (/usr/lib/php/20190902/memcached.so.so: cannot open shared object file: No such file or directory)) at Unknown#0

but the Status is:

● memcached.service - memcached daemon
     Loaded: loaded (/lib/systemd/system/memcached.service; enabled; vendor preset: enabled)
     Active: active (running) since Tue 2021-12-28 10:50:49 CET; 2min 5s ago
       Docs: man:memcached(1)
   Main PID: 235657 (memcached)
      Tasks: 10 (limit: 11879)
     Memory: 2.0M
     CGroup: /system.slice/memcached.service
             └─235657 /usr/bin/memcached -m 2560 -p 11211 -u memcache -l -P /var/run/memcached/memcached.pid

Dez 28 10:50:49 nextcloudserver systemd[1]: memcached.service: Succeeded.
Dez 28 10:50:49 nextcloudserver systemd-memcached-wrapper[118166]: Signal handled: Terminated.
Dez 28 10:50:49 nextcloudserver systemd[1]: Stopped memcached daemon.
Dez 28 10:50:49 nextcloudserver systemd[1]: Started memcached daemon.
  • i have install apt install php7.4-memcached php7.4-igbinary and now. Module 'memcached' already loaded at Unknown#0
    – stephan_me
    Dec 28, 2021 at 14:22

1 Answer 1


Your PHP installation has an incompatible version of the memcached PHP module.

You need to make sure that main PHP and its PHP memcache module are installed from the same source.

memcached service is the actual daemon that stores the data. PHP memcached module is the adapter that facilitates connections to the memcached daemon.

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