'length not known' error

[williamissirius]

I got the following error when trying to run:
python adversarial/scripts/train_adversary.py --env InvertedPendulumAdv-v1 --folder ~/rllab-adv/results

The error message:

Traceback (most recent call last): File "adversarial/scripts/train_adversary.py", line 161, in <module> args=args File "/home/zhsu/DRL/rllab-adv2/rllab-adv/rllab/policies/gaussian_mlp_policy.py", line 110, in __init__ mean_var, log_std_var = L.get_output([l_mean, l_log_std]) File "/home/zhsu/DRL/env/lib/python3.5/site-packages/lasagne/layers/helper.py", line 185, in get_output all_outputs[layer] = layer.get_output_for(layer_inputs, **kwargs) File "/home/zhsu/DRL/rllab-adv2/rllab-adv/rllab/core/lasagne_layers.py", line 30, in get_output_for tiled = TT.tile(reshaped_param, tile_arg, ndim=ndim) File "/home/zhsu/DRL/env/lib/python3.5/site-packages/theano/tensor/basic.py", line 4398, in tile for r in reps]): File "/home/zhsu/DRL/env/lib/python3.5/site-packages/theano/tensor/basic.py", line 4395, in <listcomp> if not numpy.all([isinstance(r, integer_types) or File "/home/zhsu/DRL/env/lib/python3.5/site-packages/theano/tensor/var.py", line 514, in __iter__ for i in xrange(theano.tensor.basic.get_vector_length(self)): File "/home/zhsu/DRL/env/lib/python3.5/site-packages/theano/tensor/basic.py", line 3907, in get_vector_length raise ValueError("length not known") ValueError: length not known