This is Kolab Winterfell on Fedora 26.

I get this error:

PHP Fatal error: Uncaught Error: [] operator not supported for strings in /usr/share/kolab-webadmin/lib/kolab_client_output.php:159

The variable script is initialised as a string, but then used as an array.
https://cgit.kolab.org/webadmin/tree/lib/kolab_client_output.php#n148
It seems the version of PHP (7.1.8) in Fedora 26 does not like that.