Just a few days ago Fortinet released new version of their SSLVPN utilities.
As of version 4.4.2313 Fortinet modified quite a few files resp. deleted some .sh files as for example the sysconfig.linux.sh file were we made the Ubuntu 15.04 changes. Also when you start the program it still shows version 4.4.2312 which means they forgot to increment the version number. Until now I only tested for Ubuntu 14.04 32/64bit, your are welcome to test for other OS variants.
Have fun with the packages, you can find it as usual on the project page.