RuntimeError: Handle cam_over_shoulder_left_mask does not exist.

[xiangbaihan]

when I running "python task_builder.py",I got those error:
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Traceback (most recent call last):
File "task_builder.py", line 289, in
scene = Scene(pr, robot, obs_config)
File "/home/xbh/RLBench/tools/../rlbench/backend/scene.py", line 50, in init
self._cam_over_shoulder_left_mask = VisionSensor(
File "/home/xbh/.local/lib/python3.8/site-packages/pyrep/objects/vision_sensor.py", line 14, in init
super().init(name_or_handle)
File "/home/xbh/.local/lib/python3.8/site-packages/pyrep/objects/object.py", line 24, in init
self._handle = sim.simGetObjectHandle(name_or_handle)
File "/home/xbh/.local/lib/python3.8/site-packages/pyrep/backend/sim.py", line 94, in simGetObjectHandle
raise RuntimeError('Handle %s does not exist.' % objectName)
RuntimeError: Handle cam_over_shoulder_left_mask does not exist.
QObject::~QObject: Timers cannot be stopped from another thread
QMutex: destroying locked mutex
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what should I do?