Meine Mail-App geht irgendwie nicht

Hallo ich bekomme seit dem Update auf NC 20 eine Fehlermeldung, wenn ich die App Mail aktivieren will. Vor dem Update lief alles einwandfrei. Alle Updates habe ich schrittweise durchgeführt. PHP 7.3 ist installiert.

grafik

Was will mir diese Meldung sagen?

root@nextclxxxx:/var/www/nextcloud# sudo -u www-data php -f occ app:check-code mail Analysing /var/www/nextcloud/apps/mail/lib/Vendor/Favicon/Favicon.php 6 errors line 53: != - is discouraged line 53: != - is discouraged line 191: == - is discouraged line 262: == - is discouraged line 274: == - is discouraged line 279: == - is discouraged App is not compliant root@nextclxxxx:/var/www/nextcloud# sudo -u www-data php -f occ app:remove mail mail disabled mail 0 removed root@nextclxxxx:/var/www/nextcloud# sudo -u www-data php -f occ app:install mail An unhandled exception has been thrown: Error: Class 'Horde_Mail_Rfc822_Address' not found in /var/www/nextcloud/apps/mail/lib/Migration/FixCollectedAddresses.php:72 Stack trace: #0 /var/www/nextcloud/apps/mail/lib/Migration/FixCollectedAddresses.php(56): OCA\Mail\Migration\FixCollectedAddresses->fixAddress(Object(OCA\Mail\Db\CollectedAddress), Object(OC\Repair)) #1 /var/www/nextcloud/lib/private/Repair.php(111): OCA\Mail\Migration\FixCollectedAddresses->run(Object(OC\Repair)) #2 /var/www/nextcloud/lib/private/legacy/OC_App.php(1042): OC\Repair->run() #3 /var/www/nextcloud/lib/private/Installer.php(160): OC_App::executeRepairSteps('mail', Array) #4 /var/www/nextcloud/core/Command/App/Install.php(68): OC\Installer->installApp('mail') #5 /var/www/nextcloud/apps/bookmarks/vendor/symfony/console/Command/Command.php(255): OC\Core\Command\App\Install->execute(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput)) #6 /var/www/nextcloud/apps/bookmarks/vendor/symfony/console/Application.php(1009): Symfony\Component\Console\Command\Command->run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput)) #7 /var/www/nextcloud/apps/bookmarks/vendor/symfony/console/Application.php(273): Symfony\Component\Console\Application->doRunCommand(Object(OC\Core\Command\App\Install), Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput)) #8 /var/www/nextcloud/apps/bookmarks/vendor/symfony/console/Application.php(149): Symfony\Component\Console\Application->doRun(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput)) #9 /var/www/nextcloud/lib/private/Console/Application.php(215): Symfony\Component\Console\Application->run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput)) #10 /var/www/nextcloud/console.php(100): OC\Console\Application->run() #11 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...') root@nextclxxxx:/var/www/nextcloud# sudo -u www-data php -f occ app:enable mail An unhandled exception has been thrown: Error: Class 'Horde_Mail_Rfc822_Address' not found in /var/www/nextcloud/apps/mail/lib/Migration/FixCollectedAddresses.php:72 Stack trace: #0 /var/www/nextcloud/apps/mail/lib/Migration/FixCollectedAddresses.php(56): OCA\Mail\Migration\FixCollectedAddresses->fixAddress(Object(OCA\Mail\Db\CollectedAddress), Object(OC\Repair)) #1 /var/www/nextcloud/lib/private/Repair.php(111): OCA\Mail\Migration\FixCollectedAddresses->run(Object(OC\Repair)) #2 /var/www/nextcloud/lib/private/legacy/OC_App.php(1042): OC\Repair->run() #3 /var/www/nextcloud/lib/private/Installer.php(160): OC_App::executeRepairSteps('mail', Array) #4 /var/www/nextcloud/core/Command/App/Enable.php(123): OC\Installer->installApp('mail', false) #5 /var/www/nextcloud/core/Command/App/Enable.php(93): OC\Core\Command\App\Enable->enableApp('mail', Array, false, Object(Symfony\Component\Console\Output\ConsoleOutput)) #6 /var/www/nextcloud/apps/bookmarks/vendor/symfony/console/Command/Command.php(255): OC\Core\Command\App\Enable->execute(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput)) #7 /var/www/nextcloud/apps/bookmarks/vendor/symfony/console/Application.php(1009): Symfony\Component\Console\Command\Command->run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput)) #8 /var/www/nextcloud/apps/bookmarks/vendor/symfony/console/Application.php(273): Symfony\Component\Console\Application->doRunCommand(Object(OC\Core\Command\App\Enable), Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput)) #9 /var/www/nextcloud/apps/bookmarks/vendor/symfony/console/Application.php(149): Symfony\Component\Console\Application->doRun(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput)) #10 /var/www/nextcloud/lib/private/Console/Application.php(215): Symfony\Component\Console\Application->run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput)) #11 /var/www/nextcloud/console.php(100): OC\Console\Application->run() #12 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')