today I tried to update some Ubuntu 16 machines to the latest and greatest Zabbix release.
Unfortunately, apt fails installing the zabbix-frontend-php package, apparently because of a syntax error in the postinst script:

Setting up linux-generic (4.4.0.97.102) ...
Setting up linux-libc-dev:amd64 (4.4.0-97.120) ...
Setting up zabbix-agent (1:3.4.3-1+xenial) ...
Setting up zabbix-frontend-php (1:3.4.3-1+xenial) ...
/var/lib/dpkg/info/zabbix-frontend-php.postinst: 11: /var/lib/dpkg/info/zabbix-frontend-php.postinst: Syntax error: "then" unexpected (expecting "done")
dpkg: error processing package zabbix-frontend-php (--configure):
subprocess installed post-installation script returned error exit status 2
Setting up zabbix-get (1:3.4.3-1+xenial) ...
Setting up zabbix-sender (1:3.4.3-1+xenial) ...
Processing triggers for libc-bin (2.23-0ubuntu9) ...