I'm getting this issue when running
import gym
env = gym.make('Ant-v2')

Mujoco works fine on my machine, I can get the simulations up and running. I've seen this thread but none of the suggestions seem to help.

Any debugging suggestions? What .so files should I expect to have? Where should I expect to find them? What packages should I have installed via apt-get? I'm wondering if one of my installations went wrong somehow.

I'm running on Ubuntu 16.04 with an NVIDIA GeForce GTX 980M graphics card and graphics drivers installed, though I'm not sure that's relevant to this problem.