The iRony configuration for Apache is broken in Kolab 16 on Ubuntu Xenial.
ls -l /etc/apache2/sites-available total 32 -rw-r--r-- 1 root root 1332 mar 19 2016 000-default.conf -rw-r--r-- 1 root root 851 lis 14 12:46 chwala.conf -rw-r--r-- 1 root root 6338 kwi 5 2016 default-ssl.conf -rw-r--r-- 1 root root 631 maj 10 12:18 irony.conf lrwxrwxrwx 1 root root 23 maj 10 12:19 iRony.conf -> ../../iRony/apache.conf -rw-r--r-- 1 root root 352 maj 10 11:26 kolab-freebusy.conf -rw-r--r-- 1 root root 1134 sty 25 10:00 kolab-syncroton.conf lrwxrwxrwx 1 root root 32 maj 8 09:39 kolab-webadmin.conf -> ../../kolab-webadmin/apache.conf -rw-r--r-- 1 root root 1092 maj 10 11:11 roundcubemail.conf root@kolab:/etc/apache2# ls -l /etc/apache2/sites-enabled total 0 lrwxrwxrwx 1 root root 35 maj 10 12:28 000-default.conf -> ../sites-available/000-default.conf lrwxrwxrwx 1 root root 30 maj 10 12:29 chwala.conf -> ../sites-available/chwala.conf lrwxrwxrwx 1 root root 38 maj 10 12:29 kolab-freebusy.conf -> ../sites-available/kolab-freebusy.conf lrwxrwxrwx 1 root root 39 maj 10 12:29 kolab-syncroton.conf -> ../sites-available/kolab-syncroton.conf lrwxrwxrwx 1 root root 38 maj 10 12:29 kolab-webadmin.conf -> ../sites-available/kolab-webadmin.conf lrwxrwxrwx 1 root root 37 maj 10 12:29 roundcubemail.conf -> ../sites-available/roundcubemail.conf
also the iRony.conf link is broken. There's no /etc/iRony/apache.conf file.