Error during app service registration: Class 'Horde_Translation' not found

After a recent update of Nextcloud on one of my Arch Linux based servers I’m seeing lots of error messages in the log file that say Error during app service registration: Class 'Horde_Translation' not found. I can no longer access the user settings page, for instance.

Looking at the file system tree I can see that Horde is shipped with the mail app under apps/mail/mail/vendor/pear-pear.horde.org but I’m not sure if that suffices.

Any idea what went wrong here?

I forgot to mention that I’m running nextcloud 23.0.0 with php7 and fpm.

FWIW, the same issue occurs with php8.

And occ from the command line yields this:

$ php occ app:update 
An unhandled exception has been thrown:
Error: Class "Horde_Imap_Client" not found in /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php:106
Stack trace:
#0 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(106): ReflectionClass->newInstanceArgs()
#1 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(114): OC\AppFramework\Utility\SimpleContainer->buildClass()
#2 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(131): OC\AppFramework\Utility\SimpleContainer->resolve()
#3 /usr/share/webapps/nextcloud/lib/private/AppFramework/DependencyInjection/DIContainer.php(463): OC\AppFramework\Utility\SimpleContainer->query()
#4 /usr/share/webapps/nextcloud/lib/private/AppFramework/DependencyInjection/DIContainer.php(435): OC\AppFramework\DependencyInjection\DIContainer->queryNoFallback()
#5 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(56): OC\AppFramework\DependencyInjection\DIContainer->query()
#6 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(182): OC\AppFramework\Utility\SimpleContainer->get()
#7 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(160): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}()
#8 /usr/share/webapps/nextcloud/3rdparty/pimple/pimple/src/Pimple/Container.php(114): OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}()
#9 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(127): Pimple\Container->offsetGet()
#10 /usr/share/webapps/nextcloud/lib/private/AppFramework/DependencyInjection/DIContainer.php(457): OC\AppFramework\Utility\SimpleContainer->query()
#11 /usr/share/webapps/nextcloud/lib/private/AppFramework/DependencyInjection/DIContainer.php(435): OC\AppFramework\DependencyInjection\DIContainer->queryNoFallback()
#12 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(87): OC\AppFramework\DependencyInjection\DIContainer->query()
#13 [internal function]: OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}()
#14 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(106): array_map()
#15 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(114): OC\AppFramework\Utility\SimpleContainer->buildClass()
#16 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(131): OC\AppFramework\Utility\SimpleContainer->resolve()
#17 /usr/share/webapps/nextcloud/lib/private/AppFramework/DependencyInjection/DIContainer.php(463): OC\AppFramework\Utility\SimpleContainer->query()
#18 /usr/share/webapps/nextcloud/lib/private/AppFramework/DependencyInjection/DIContainer.php(435): OC\AppFramework\DependencyInjection\DIContainer->queryNoFallback()
#19 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(87): OC\AppFramework\DependencyInjection\DIContainer->query()
#20 [internal function]: OC\AppFramework\Utility\SimpleContainer->OC\AppFramework\Utility\{closure}()
#21 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(106): array_map()
#22 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(114): OC\AppFramework\Utility\SimpleContainer->buildClass()
#23 /usr/share/webapps/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(131): OC\AppFramework\Utility\SimpleContainer->resolve()
#24 /usr/share/webapps/nextcloud/lib/private/AppFramework/DependencyInjection/DIContainer.php(463): OC\AppFramework\Utility\SimpleContainer->query()
#25 /usr/share/webapps/nextcloud/lib/private/ServerContainer.php(145): OC\AppFramework\DependencyInjection\DIContainer->queryNoFallback()
#26 /usr/share/webapps/nextcloud/lib/private/Console/Application.php(217): OC\ServerContainer->query()
#27 /usr/share/webapps/nextcloud/lib/private/Console/Application.php(128): OC\Console\Application->loadCommandsFromInfoXml()
#28 /usr/share/webapps/nextcloud/console.php(98): OC\Console\Application->loadCommands()
#29 /usr/share/webapps/nextcloud/occ(11): require_once('/usr/share/weba...')
#30 {main}

This is very much a default install without any tweaks.

Resolved by disabling the Mail app.