Bug / Crash After update I get "ArgumentNullException: Value cannot be null"

[josemendez]

Thanks for that.
I did check all my mesh colliders, and I didn't find one which was null.

Even with your modification, I am getting a NullReferenceException *at the same moment* that I press the Play button (that is: BEFORE the scene is played):
(then I get this exception once per frame)


NullReferenceException: Object reference not set to an instance of an object
Obi.ObiParticleRenderer.get_ParticleMeshes () (at Assets/Obi/Scripts/Common/Rendering/ObiParticleRenderer.cs:27)
Obi.FluidRenderingUtils.VolumeReconstruction (UnityEngine.Rendering.CommandBuffer cmd, Obi.FluidRenderingUtils+FluidRenderTargets renderTargets, UnityEngine.Material thickness_Material, UnityEngine.Material colorMaterial, Obi.ObiParticleRenderer[] renderers) (at Assets/Obi/Scripts/Fluid/Rendering/FluidRenderingUtils.cs:137)
Obi.ObiFluidRenderer.UpdateFluidRenderingCommandBuffer () (at Assets/Obi/Scripts/Fluid/Rendering/ObiFluidRenderer.cs:118)
Obi.ObiBaseFluidRenderer.OnPreRender () (at Assets/Obi/Scripts/Fluid/Rendering/ObiBaseFluidRenderer.cs:80)
UnityEngine.GUIUtility: ProcessEvent(Int32, IntPtr) (at /Users/bokken/buildslave/unity/build/Modules/IMGUI/GUIUtility.cs:197)

EDIT:
I think it has to do with the script ObiKinematicVelocities.cs, which seems to have been removed in the new version.

I was using this on one of the objects, because I had a fast moving platform, moving sideways, and I wanted to translate the particles on that platform. 
Is there an alternative to ObiKinematicVelocities.cs?

Hi,

ObiKinematicVelocities is now part of the core engine. You should just remove it. See the changelog for 5.6.1:

## [5.6.1]

### Fixed
- Bug in Burst backend: solver bounding box size was typically underestimated.
- Bug in Burst backend: when using volume constraints: "InvalidOperationException: The NativeContainer ApplyVolumeConstraintsBatchJob.particleIndices has not been assigned or constructed"
- Bug in Burst backend: not releasing native arrays when empty solvers -with zero actors in them- are present in the scene.
- Bug in Oni backend: volume constraints not working properly when multiple actors are present in the solver.
- Fixed crash when using ObiLateUpdater or ObiLateFixedUpdater with the Burst backend.
- Reduced GC allocation in dynamic particle attachments.
- Fixed bug in Skin constraints, that caused them to fail restricting particle movement in certain circumstances.

### Changed
- Updated Oni iOS library to XCode 12.1. Make sure to use XCode 12.1 or up to build for iOS when using the Oni backend.
- ObiKinematicVelocities component has been removed. Its functionality is now built into the engine, and automatically used for kinematic rigidbodies.

### Added
- Sample ObiContactDispatcher component, that will call custom enter/stay/exit contact events.
- Support for multiple solvers in sample script in ObiContactGrabber.
- Added util LookAroundCamera component.