The first thing to try would be to reset your prefs to see if they were corrupted. Here are the steps:
On windows the PI prefs are stored in the registry. Run the Registry Editor and navigate to the path on your system cooresponding to the below: (The specific path will vary.)
Right click on the entry for Particle_Illusion, and select Export to save a copy to the desktop.
Delete the “Particle_Illusion” key to clean them. The prefs will be reset to defaults on next relaunch of PI.
If this helps please send us a zipped copy of the faulty prefs file exported to desktop for analysis. If this doesn’t help we’ll need to dig in deeper.