I've noticed that the config file included with versions 3 and 4 can result in a window error when running the PS plugin on Windows 8. The simplest resolution is to run Notepad (or other text editor) as an administrator and edit the "Filter Forge.config" file that gets placed in the PS Plugins folder. Simply change the IndependentUI parameter to "true".
I've only tested this with the 64-bit version of the plugin on Windows 8 within Photoshop CC (the FF4 plugin used to work on Windows 8 in CS6); however, the window error that occurs prevents the plugin from being run at all.
engineer @Google, creative director @SabrageDesignStudio ... reading, writing, doing digital art and photography ... enjoying life and its fruits
