In the version 0.6.4 we have depreciated the bullet physics in favor for the faster physx. This unfortunately means that any preset you may be using that contains a bullet action may become unstable.
We recommend that you remove the old bullet action and replace it with the newer Physx action. If you have been using the bullet player controller please convert to the new Player actions. To save time you can add the preset Player - Dex_BlackKnightress and replace this model with your own then adjust some of the properties to match your model.
If you have used Lua physics you should be ok except for calling the player capsule. We will replace the lua capsule with access to the full character controller at some point.
