Exception: Not all gripper dof names were resolved to dof handles and dof indices

Hi, I’m trying to replicate the tutorial at “5.6 Adding a new manipulator” but instead of using the Cobotta I’ve added the ur5 + 2f85 gripper from Robotiq. I did everything exactly as in the tutorial but i can’t make the script run because I’m getting this error:Traceback (most recent call last):
File “/home/alexz/Desktop/ur5_project/pick_place_example.py”, line 80, in
my_world.reset()
File “/home/alexz/.local/share/ov/pkg/isaac_sim-2023.1.0-hotfix.1/exts/omni.isaac.core/omni/isaac/core/world/world.py”, line 283, in reset
self._scene._finalize(self.physics_sim_view)
File “/home/alexz/.local/share/ov/pkg/isaac_sim-2023.1.0-hotfix.1/exts/omni.isaac.core/omni/isaac/core/scenes/scene.py”, line 318, in _finalize
articulated_system.initialize(physics_sim_view)
File “/home/alexz/.local/share/ov/pkg/isaac_sim-2023.1.0-hotfix.1/exts/omni.isaac.manipulators/omni/isaac/manipulators/single_manipulator.py”, line 102, in initialize
self._gripper.initialize(
File “/home/alexz/.local/share/ov/pkg/isaac_sim-2023.1.0-hotfix.1/exts/omni.isaac.manipulators/omni/isaac/manipulators/grippers/parallel_gripper.py”, line 112, in initialize
raise Exception(“Not all gripper dof names were resolved to dof handles and dof indices.”)
Exception: Not all gripper dof names were resolved to dof handles and dof indices.

I really don’t know how to fix this, please any help would be appreciated.

This is the project folder

ur5_project.zip (9.0 MB)

I’m running Isaac Sim 2023.1.0-hotfix.1 on Ubuntu 22.04