Roundcube Plugin 0.0.8 error when i run imscp-rqst-mngr

That is the reason why the rules are not working. Did you install dovecot managesieve?

did it. Now it's possible to klick + to add Rules. But there is still the error "could not connect to server".

@TheCry

do i have to do some configuration for dovecot managesieve?

Do a Ping on you ssh console to imap.admin.your-serverhostname.tld

cannot resolve. unknown host.

That is your problem. Take a look in the main.inc.php of roundcube. There you will find the imap and smtp Server url.
This urls must be resolveable!
Add a *.admin IN A to you DNS for the panel domain. To fix it fast add the url to the /etc/hosts
Then you have to reinstall dovecot managesieve and the roundcube plugins

the url in imscp.main.inc.php is pingable.

I've reinstalled roundcube plugins & managesieve.

Same problem.

Tomorrow i can give you teamviewer support.

i had to work yesterday. sorry. maybe today?

At the moment i'm on the road