Traceback (most recent call last):


 "<string>", line 12, in <module>


 "g:\py\venv\lib\site-packages\matplotlib\backends\backend_webagg.py", line 29, in <module>

raise RuntimeError("The WebAgg backend requires Tornado.")
RuntimeError: The WebAgg backend requires Tornado.

Traceback (most recent call last):

 "tests.vi.test_marks in /Users/Home/Library/Application Support/Sublime Text 3/Installed Packages/Vintageous.sublime-package", line 35, in setUpAttributeError: 'NoneType' object has no attribute 'sel'