error in the test step.

[HzcIrving]

when I use this code to interactively view moving to landmark scenario (see others in ./scenarios/): bin/interactive.py --scenario simple.py, the error is as follows:
warnings.warn(colorize('%s: %s'%('WARN', msg % args), 'yellow')) Traceback (most recent call last): File "bin/interactive.py", line 26, in <module> env.render() File "/Volumes/SSDIrving/MACWORKSPACE/Anaconda/anaconda3/envs/PyMultiAgentworkspace/lib/python3.5/site-packages/gym/core.py", line 105, in render raise NotImplementedError NotImplementedError