AttributeError: 'NoneType' object has no attribute 'data'

[dylanthomas]

when I ran your code, it spitted out the following:

..
[2017-03-17 20:15:21,067] Making new env: PongDeterministic-v3
[2017-03-17 20:15:21,075] Making new env: PongDeterministic-v3
Process Process-3:
Traceback (most recent call last):
File "/home/john/anaconda3/envs/th/lib/python3.5/multiprocessing/process.py", line 249, in _bootstrap
self.run()
File "/home/john/anaconda3/envs/th/lib/python3.5/multiprocessing/process.py", line 93, in run
self._target(*self._args, **self._kwargs)
File "/home/john/dev/pytorch-a3c/train.py", line 24, in train
shared_param.grad.data = param.grad.data
AttributeError: 'NoneType' object has no attribute 'data'
Process Process-8:
...
...
File "/home/john/dev/pytorch-a3c/train.py", line 24, in train
shared_param.grad.data = param.grad.data
AttributeError: 'NoneType' object has no attribute 'data'
Time 00h 00m 01s, episode reward -21.0, episode length 764
...

In the end it looks like it's running. Am I right?

Then, what is the cause the error messages ?

Many thanks !

(I am running this in conda env with python 3.5)

[ikostrikov]

We have already fixed this problem. Pull recent code from the repo.