Crash in ConstraintProjectionManager

[zemlifr]

I got report from our testers that they have encountered crash in ConstraintProjectionManager. It happened multiple times with slightly different callstacks. Unortunately I dont have any repro and provided dumps are not much useful as it happened on release build and most of the stuff is optimized away. I only have these callstacks:

     PhysX_64.dll!physx::Sc::ConstraintProjectionManager::createGroupNode(physx::Sc::BodySim & b) Line 232    C++
     PhysX_64.dll!physx::Sc::ConstraintProjectionManager::addToGroup(physx::Sc::BodySim & b, physx::Sc::BodySim * other, physx::Sc::ConstraintSim & c) Line 304    C++
     PhysX_64.dll!physx::Sc::ConstraintProjectionManager::processPendingUpdates(physx::PxcScratchAllocator & scratchAllocator) Line 442    C++
     PhysX_64.dll!physx::Sc::Scene::stepSetupCollide(physx::PxBaseTask * continuation) Line 3710    C++
     PhysX_64.dll!physx::Sc::Scene::simulate(float timeStep, physx::PxBaseTask * continuation) Line 1509    C++
     PhysX_64.dll!physx::Cm::Task::run() Line 67    C++

And

PhysX_64.dll!physx::shdfnd::PoolBase<physx::Sc::ConstraintGroupNode,physx::shdfnd::ReflectionAllocator<physx::Sc::ConstraintGroupNode> >::~PoolBase<physx::Sc::ConstraintGroupNode,physx::shdfnd::ReflectionAllocator<physx::Sc::ConstraintGroupNode> >() Line 61    C++
   PhysX_64.dll!physx::Sc::Scene::release() Line 988    C++
   PhysX_64.dll!physx::Scb::Scene::release() Line 365    C++
   PhysX_64.dll!physx::NpScene::~NpScene() Line 183    C++
   PhysX_64.dll!physx::NpScene::`scalar deleting destructor'(unsigned int)    C++
   PhysX_64.dll!physx::NpPhysics::releaseSceneInternal(physx::PxScene & scene) Line 326    C++

Any idea what could casue this?