Unity 5.6 beta Cloth crash

Hi, i use Unity 5.6 beta cloth for animate 2 simple flags but the console show hundreds of red messages like this: [Physics.PhysX] Call to PxCloth::setExternalAcceleration() not allowed while simulation is running.
[Physics.PhysX] Call to PxCloth::getWorldBounds() not allowed while simulation is running.
and then in few seconds Unity crash, i try with many versions (in my case crash occurs in all 5.6 beta versions that i use, b5 to b11) but the problem remains, information about this problem doesnt exist in Unity or other forums, In Unity 5.5 all work fine but I cant return to the 5.5 version because new assets that i use (like post processing stack) doesnt work fine, thanks for your help.

 

Hi, in the Unity beta 5.6.0f1 published yesterday (i not understand the letter F in the beta version, looks like a RC or final version) the problem (in my case) is complety solved, thanks.