First physics issue: I was trying to setup a scene with my polar bear which uses displacement and soft cloth physics so the displacement/fur works with the wind (which it does work properly with any animations directly from the cc4 player but not from the content library even if they are the same animations)

What happens when I use newer animations from the content library is that as soon as it's played, the displacement hair explodes into long spikes and makes the bear look like a porcupine.

Second issue:
Using either a combination of constraints with other physics such as the bear using cloth that are disabled in the scene or other props also hidden using constraints make the physics of one prop visible become very unstable and often crashes iclone. I'd often use the puppet prop tool to test.

Upon recovery, usually two physics icons/tabs would show side by side -as if it's trying to load two physics props in the same panel at the same time. I will update this later with images, system info and a project file you can test.