change domain of an account gives an error with httpd service

I tried to change the domain of one of the accounts on a server with Debian 9 + DirectAdmin. I do this via the DA user panel (log in as the user and than Domain Setup -> Change a Domain Name). Changing to domain here goes well without error. But after that I caot reach the domain and when I try to restart the httpd service in the DA admin panel I get this error:

/bin/systemctl restart httpd.service >/dev/null 2>&1

See the image:

FgvA8.jpg

When I change the domain back to the original I can start the httpd service and everything works as well again.

Any ideas how to fix this?