Error when picking objects with Surface Gripper in Omniverse

Hello,

I am trying to pick an object in Omniverse by using „REB_SurfaceGripper“-module and sending commands via Isaac SDK. This works fine when using the „sortbot_sim.usd“ sample. I tried to transfer this functionality to a scene with an own simple robot, which only has a prismatic joint which moves up and down and is supposed to pick up a „small_KLT“. But here I get the following error messages at the moment the gripper touches the object:

2021-04-15 10:36:45 [12,383,899ms] [Error] [omni.isaac.dynamic_control.plugin] DcGetRigidBodyPose: Invalid or expired body handle
2021-04-15 10:36:45 [12,383,899ms] [Error] [omni.isaac.dynamic_control.plugin] DcSetRigidBodyDisableGravity: Invalid or expired body handle

The output channel „iostate“ of REB_SurfaceGripper outputs 1, but after that error I can not control the robot with „REB_JointControl“ anymore. It does not react to my commands until I open the gripper. The object to be grasped is set as a rigid body and has mass properties.

Could you tell me what causes these errors and how i can solve it?
Any help would be greatly appreciated, thanks!
Gripper_Test_Robot.zip (14.2 KB)

@v.maidhof This is a bug where in order to grab a physics enabled object it has to be registered with a rigid body sink. The bug has been fixed for the next release.
See video for details, but you can create a rigid body sink and set its reference to the SmallKLT prim and then press play. This will work around the issue.

Thank you very much @Hammad_M . Now it works.