I've had this problem already in the past, but now are quite a few plugins affected.
See attached screenshot.
None of the plugins find and load their standard presets (or banks) even if they are there, and loading manually ...
FLStudio 12's demo to my Windows 8.1 laptop, I set up installation so that the FLStudio 12 folder will sit PC < C: (Windows) < Program Files (x86) < Image-Line, and VST files in Program Files ...