Connection timed out (PR_IO_TIMEOUT-ERROR) when loadind a notebook

FAQ on notebooks
#1

I got this error once loading the Wrap-up quiz 4 and I couldn’t display it anymore.

Image collée à 2021-5-10 09-48
Image collée à 2021-5-10 09-48761×493 37.1 KB

To fix the problem and thanks to this post in askubuntu.com, I did:

  • start Firefox
  • go to about:profiles
  • note the name of the current profile
  • rename the current profile folder to xxxx.default.HOLD
  • restart Firefox
#2

This is slightly weird. I would expect this was a temporary problem with the JupyterHub server rather than something related with your firefox profile. Let’s see if it happens again after the MOOC officially starts …

#3

Greetings,

I’m having this problemas well, and Firefox is my main choice.

Hopefully it can be identified and solved soon.

Thanks in advance.

#4

I don’t expect this to be related to Firefox (or any particular browser) but more to be a problem on the server side (i.e. the JupyterHub that is used for the Jupyter notebook inside the FUN MOOC platform). I edited the topic to remove the Firefox mention.

@obrito if you give us more information how that happens maybe it could help:

  • did you get this error only once or twice?
  • do you get this error quite regularly, if yes how often, e.g. 3-4 times in a single day, 3-4 times each day for many days in a row, etc …
  • does it go away if you try to refresh the page (F5 in Firefox I think)?
  • do you see this problem on some notebooks in particular?

cc @brospars in case he has some insights to debug the problem further.

#5

I’ve got no logs of such error on the server side and this seems to be a network/DNS issue.
@obrito Do you use a VPN or proxy ?

The weird thing is that Laurence couldn’t access the server until she deleted her Firefox profile. This makes me think of a cached dns issue or something like that.

#6

Thanks everyone,

I managed to solve it. I had to erase the browsing history, cache and cookies from the Firefox browser.

Best regards,
Omar