I think:
A. you need to update your CUDA drivers.

  
      askubuntu.com
  
  
      
    
  

  How can I install CUDA on Ubuntu 16.04? 14



  16.04, cuda



  asked by
  
  
    Martin Thoma
  
  on 03:44AM - 16 Jul 16


  
  
    
    
  
  


https://xcat-docs.readthedocs.io/en/stable/advanced/gpu/nvidia/verify_cuda_install.html 10
https://devtalk.nvidia.com/default/topic/1027653/how-do-i-check-if-i-install-cuda-and-cudnn-successfully-/ 9
B. then, I suggest you install the pytorch binaries again
conda install pytorch torchvision -c pytorch