# URDF Error when turning on Collision Manager for RE2

**URL:** <https://forum.hello-robot.com/t/urdf-error-when-turning-on-collision-manager-for-re2/700>\
**Category:** Ask\
**Created:** [May 8, 2023, 12:12am UTC](https://forum.hello-robot.com/t/urdf-error-when-turning-on-collision-manager-for-re2/700 "2023-05-08T00:12:28Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jehan](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/jehan/32/347_2.png) [@jehan](https://forum.hello-robot.com/u/jehan)\
**Post date:** [May 8, 2023, 12:12am UTC](https://forum.hello-robot.com/t/urdf-error-when-turning-on-collision-manager-for-re2/700/1 "2023-05-08T00:12:28Z")

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Hello,

I’m trying to turn on the default collision manager for the RE2, however when I change the `stretch_user_params.yaml` file so that the `robot` attribute `use_collision_manager` is set to `1`, I get this error with `stretch_body.robot.startup()`:

````auto
In [6]: r.startup()
Out[6]: False

Exception in thread Thread-5:
Traceback (most recent call last):
  File "/usr/lib/python3.8/threading.py", line 932, in _bootstrap_inner
    self.run()
  File "/home/jehanyang/.local/lib/python3.8/site-packages/stretch_body/robot.py", line 88, in run
    self.robot.collision.step()
  File "/home/jehanyang/.local/lib/python3.8/site-packages/stretch_body/robot_collision.py", line 97, in step
    new_limits=m.step(status)
  File "/home/jehanyang/.local/lib/python3.8/site-packages/stretch_tool_share/stretch_dex_wrist/collision_model.py", line 53, in step
    pose = self.fk.tool_fk(cfg, 'link_gripper_fingertip_left')
  File "/home/jehanyang/.local/lib/python3.8/site-packages/stretch_body/robot_collision.py", line 155, in tool_fk
    joint_cfg = self.robot_model._process_cfg(cfg)
AttributeError: 'URDF' object has no attribute '_process_cfg'```
````

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<div class="post-metadata">

**Author:** ![bshah](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.hello-robot.com/bshah/32/55_2.png) [@bshah](https://forum.hello-robot.com/u/bshah)\
**Post date:** [May 8, 2023, 7:53pm UTC](https://forum.hello-robot.com/t/urdf-error-when-turning-on-collision-manager-for-re2/700/2 "2023-05-08T19:53:05Z")

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Thanks for reporting this @jehan, I’m beginning to look into this issue and I’d like to replicate the AttributeError on my robot. Can you tell me what version of Stretch Body and urdfpy you have installed? You can run `pip3 list` and copy/paste the output here.