Webserver doesn't work after update to macOS 10.13.2

My webserver went well bevor doing update from macOS High Sierra 10.13.1 to 10.13.2

Syslog shows:

Dec 17 16:25:18 iMac-XXX com.apple.xpc.launchd[1] (org.apache.httpd[9719]): Service exited with abnormal code: 1

Dec 17 16:25:18 iMac-XXX com.apple.xpc.launchd[1] (org.apache.httpd): Service only ran for 0 seconds. Pushing respawn out by 10 seconds.

... repeating this message every 10 seconds.

httpd.conf hasn't changed.

Is there someone with an idea?