MediaWiki - update error

Once you upgrade to version 20.5, you cannot update your MediaWiki.
Error during installation of the application: (‘mediawiki’, ‘Error: Missing one or more required components of PHP.\nYou are missing a required extension to PHP that MediaWiki needs.\nPlease install:\n * mbstring\n * xml\n\n’, ‘PHP Warning: PHP Startup: Unable to load dynamic library ‘’ (tried: /usr/lib/php/20190902/ (/usr/lib/php/20190902/ undefined symbol: zif_apcu_store), /usr/lib/php/20190902/ (/usr/lib/php/20190902/ cannot open shared object file: No such file or directory)) in Unknown on line 0\nTraceback (most recent call last):\n File “/usr/share/plinth/actions/mediawiki”, line 230, in \n main()\n File “/usr/share/plinth/actions/mediawiki”, line 226, in main\n subcommand_method(arguments)\n File “/usr/share/plinth/actions/mediawiki”, line 136, in subcommand_update\n subprocess.check_call([‘php’, update_script, ‘–quick’])\n File “/usr/lib/python3.7/”, line 363, in check_call\n raise CalledProcessError(retcode, cmd)\nsubprocess.CalledProcessError: Command ‘[‘php’, ‘/usr/share/mediawiki/maintenance/update.php’, ‘–quick’]’ returned non-zero exit status 1.\n’)

FreedomBox on Raspberry Pi 3+

Can you check if php-mbstring and php-xml packages are installed? (They should have been installed, as they are dependencies of mediawiki.)

yes, they’re installed.Scr2