Crash when particles and cooked mesh collides.

Hello i am caring out a excavator project. Excavator will dig the ground and fluids.

For digging ground and mud, i will try to handle this with particles(fluid). I created particles and emitters in sample vehicle scene to understand how external rigidbodies effect the particles and play with the particle attributes.

In sample vehicle scene, when particle hits ground, it crashes in one of the worker threads. When i call same code from sample particle scene, it is okay. is this happening because of cooking? Because sample vehicle scene, terrain is cooked. What should I do?

Also i tried the particle system in our simulation engine. when the particles hits on a cooked triangular mesh(our terrain) it crashes. Then i try to create particles to an uncooked dynamic and kinematic box actor, it does not crash. Please help.