BokehJS library missing; plots won't show in jlab

This is in a fresh environment, just set up with conda install -c holoviz hvplot and installing the jupyterlab comms with jupyter labextension install @pyviz/jupyterlab_pyviz. This echoes this from stack overflow, but I see it wasn’t tagged with holoviews: https://stackoverflow.com/questions/66474476/bokehjs-library-missing-error-and-no-plot

ALL software version info

holoviews 1.14.2 bokeh 2.3.0 hvplot 0.7.1 jupyterlab 2.2.6 mac OS 10.14.6 chrome 88.0.4324.182

Description of expected behavior and the observed behavior

Expected that plots show up.

Complete, minimal, self-contained example code that reproduces the issue

import hvplot.pandas
import pandas as pd
import numpy as np

df = pd.DataFrame({'x': np.random.random(100), 'y': np.random.random(100)})
df.hvplot('x', 'y')

Stack traceback and/or browser JavaScript console output

index.es6.js:211 Error: Cannot send
    at a.send (comm.js:119)
    at l._disposePlot (renderer.js:192)
    at l.dispose (renderer.js:215)
    at t.dispose (index.es6.js:2599)
    at t.e.dispose (index.es6.js:919)
    at _clear (widget.js:298)
    at _.onModelChanged (widget.js:223)
    at m (index.es6.js:459)
    at Object.c [as emit] (index.es6.js:416)
    at e.emit (index.es6.js:99)
JGtG.t.exceptionHandler @ index.es6.js:211
m @ index.es6.js:462
c @ index.es6.js:416
e.emit @ index.es6.js:99
_onListChanged @ model.js:231
m @ index.es6.js:459
c @ index.es6.js:416
e.emit @ index.es6.js:99
clear @ observablelist.js:238
clear @ model.js:144
clearExecution @ model.js:311
t @ widget.js:781
a @ actions.js:1341
(anonymous) @ actions.js:1292
o @ actions.js:1292
d @ actions.js:399
execute @ index.js:690
e.execute @ index.es6.js:357
e._executeKeyBinding @ index.es6.js:517
e.processKeydownEvent @ index.es6.js:456
e.evtKeydown @ index.es6.js:355
e.handleEvent @ index.es6.js:311
VM861:19 Bokeh: ERROR: Unable to run BokehJS code because BokehJS library is missing

[neighthan]

Just updating panel wasn’t working for me, but I think I wasn’t getting the newest version, probably due to something else requiring an older one. I ran conda update --all -c pyviz -c conda-forge, as also suggested in #4875 (after also clearing all outputs, clearing cache, and hard reloading), and now things are rendering again.

[MikeB2012]

Following advice in issue #4875 to update panel (conda install panel -c pyviz) seemed to clear up this problem for me. Could be a coincidence?