List of bugs fixed is to be found at the official forums; Z3.invisionfree.com
If you have already installed v 3.18 beta 3 on Windows,
you can download extract & replace patch here
you can download extract & replace patch here

Full windows installation package here
(use this if you don't have v 3.18 beta 3,
or if you don't know how to apply an extract & replace patch)
64 bit Ubuntu 12.04 & 12.10, Linux mint 13-15, Debian 8.0 jessie