WebIO plugin not found issue

[Gideon Simpson]

After restarting my jupyter server after doing some updates (it's an Anaconda 3 installation), I get the following error:

me@server:~$ jupyter notebook

WebIO config in ~/.jupyter/jupyter_notebook_config.py but WebIO plugin not found

[W 12:06:40.231 NotebookApp] Error loading server extension jlstaticserve

    Traceback (most recent call last):

      File "/anaconda3/lib/python3.6/site-packages/notebook/notebookapp.py", line 1546, in init_server_extensions

        mod = importlib.import_module(modulename)

      File "/anaconda3/lib/python3.6/importlib/__init__.py", line 126, in import_module

        return _bootstrap._gcd_import(name[level:], package, level)

      File "<frozen importlib._bootstrap>", line 994, in _gcd_import

      File "<frozen importlib._bootstrap>", line 971, in _find_and_load

      File "<frozen importlib._bootstrap>", line 953, in _find_and_load_unlocked

    ModuleNotFoundError: No module named 'jlstaticserve'

[I 12:06:40.266 NotebookApp] JupyterLab extension loaded from /anaconda3/lib/python3.6/site-packages/jupyterlab

[I 12:06:40.266 NotebookApp] JupyterLab application directory is /anaconda3/share/jupyter/lab

[I 12:06:40.270 NotebookApp] Serving notebooks from local directory: /Users/guardian/notebooks

[I 12:06:40.270 NotebookApp] The Jupyter Notebook is running at:

[I 12:06:40.271 NotebookApp] https://(titan or 127.0.0.1):9999/

[I 12:06:40.271 NotebookApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).

The jupyter server works, but my extensions pane is gone.  Any suggestions on how to clear this up?