[horde] mail is not activated

[Ferdinand Gruber]

Hi,

I was able to upgrade horde using the simple command

composer upgrade

But after the upgrade login is no longer possible. I get the message

mail is not activated ... on line 1550 of 
"/srv/www/htdocs/horde/vendor/horde/core/lib/Horde/Registry.php"

The authentcation should be done via the application imp. The config 
file /srv/www/htdocs/horde/web/horde/config/conf.php looks normal - 
nothing was changed by the upgrade process.

In former horde there was a file imp/config/backends.local.php where the 
backend was configured. Is this file still necessary in the current 
version of Horde? It does not exist in my horde installation in 
/srv/www/htdocs/horde/vendor/horde/imp/config

Please help.

-- 

Regards from Austria
Ferdinand Gruber