Well it was bound to happen. One plugin install kills another install. Such is the case with the new FxFactory Pro which no longer officially supports Final Cut Pro 7. And if you, like me, are using Premiere Pro CC 2015 you found out that you had to have Yosemite and install the new FXFactory Pro.
FXFactory will not even load into CC 2015 unless it's the latest version. Thus - if your PPro 2015 edits use some of the Noise Industry plug-ins, you're forced to either upgrade, or abandon FXFactory.
I bit the bullet and upgraded to 10.10.4 and 5.0.3. And FXfactory loaded happily.
Now for the rock part.
I had to do some edits to an old project in Final Cut Pro 7 that uses extensive FXfactory FX. Guess what. FXfactory 5.0.3 does not load into Final Cut Pro 7.
Thanks For that little nasty surprise there. But that's what Boot drive clones with a backup of Mavericks are for.