OccupancyGrid' object has no attribute '_slot_types' #638

[jesusramondovale]

• Library Version: latest
• ROS Version: Humble
• Platform / OS: Ubuntu 22.04

I'm using ros3djs on my ASP.NET webpage (cshtml) and when I try to visualize a 3D map the ros_server service executed in my ROS machine stops and gives the error :

"OccupancyGrid' object has no attribute '_slot_types'"

`File "/opt/ros/humble/local/lib/python3.10/dist-packages/rosbridge_library/capabilities/subscribe.py", line 159, in _publish
    self.publish(message, self.fragment_size, self.compression)
  File "/opt/ros/humble/local/lib/python3.10/dist-packages/rosbridge_library/capabilities/subscribe.py", line 318, in publish
    outgoing_msg = message.get_cbor(outgoing_msg)
  File "/opt/ros/humble/local/lib/python3.10/dist-packages/rosbridge_library/internal/outgoing_message.py", line 38, in get_cbor
    outgoing_msg["msg"] = self.get_cbor_values()
  File "/opt/ros/humble/local/lib/python3.10/dist-packages/rosbridge_library/internal/outgoing_message.py", line 33, in get_cbor_values
    self._cbor_values = extract_cbor_values(self._message)
  File "/opt/ros/humble/local/lib/python3.10/dist-packages/rosbridge_library/internal/cbor_conversion.py", line 53, in extract_cbor_values
    for slot, slot_type in zip(msg.__slots__, msg._slot_types):
AttributeError: 'OccupancyGrid' object has no attribute '_slot_types'`

[dzw-tw]

I also have this problem, have you solved it?

[chanhhoang99]

For whom who get this error, I believe you are installing your rosbridge_suite from apt which is out of date.
I tried building rosbridge_suite from source, seems to work fine at least with ros3djs.
Of it's still not working, you may try to set compression value to false