Cannot run Filter Forge 4 - the program is already running?

Hi together,

I hope somebody can help me with this Problems of Filter Forge 4 on my Windows 7,64-Bit System.
I have some Adobe Photoshop Version like CS 5, CS 6 and Adobe CC on my System and want to use Filter Forge 4 for this Versions.
I installed Filter Forge 4 (as Plugins of this Photoshop Versions) and the purchased libraries (under AppData) and running e.g. Photoshop CS 5 of the 32-Bit Modus, it Shows Filter Forge 4 under the filters but if I try to use it, it Comes an error message: Cannot run Filter Forge - the program is already running.
I re-install Filter Forge, I can't install and standalone Version (it's Grey)???
What's going wrong?

I hope somebody knows a way to use FF4 again.

Greetings Amigo