kcpevey
commented
4 months ago This happened to me again today. Here is what I tried:
- browser refresh alone - didn't fix
- browser refresh and kernel restart clear all - didn't fix
- kernel restart clear all, save, and then browser refresh - fixed it
Preliminary Checks
Summary
I've had a situation happen a few times where I was working with Panel one day and I come back the next day and the app will no longer display in a jupyter notebook. This happens with no changes to the notebook, or the environment.
Looking in the java console, at the beginning of the traceback there is a statement
Bokeh: BokehJS was loaded multiple times but one version failed to initialize.Then, every time you try to visualize a panel object the java console showsERROR: Unable to run Panel code because Bokeh or Panel library is missing.I've spent loads of time trying to figure out how it got in this state and I've gotten nowhere. The workaround I've been using for a while is to shut down my server, and open an incognito window and restart the server there. So I'm fairly certain this is a caching issue of some sort.
Today I discovered a better solution - if you shutdown ALL your open kernels, restart and clear all in the notebook, save the notebook, then REFRESH the whole browser page... it will start working again. Note - if you simple restart and clear all on just one notebook, it will not fix it.
I'm not sure why this is happening, but I've had to deal with this enough times and have spent enough time being baffled, that I think its worth an FAQ mention on how to fix.
Steps to Resolve this Issue
If this happens again, I'd first want to check if a browser refresh alone would work, then I'd add these other steps in one by one. Since I can't reproduce the error, I'm not sure what is the minimal required.