jupyterhub + jupyter '_xsrf' argument missing from POST

[Rafel Amer Ramon]

Hi!,

I have install jupyter and jupyterhub in a debian 10 machine. jupyter is installed with apt:

apt install jupyter jupyter-core python3-notebook python3-qtconsole \

jupyter-nbformat jupyter-notebook jupyter-qtconsole

and jupyter hub is installed with pip:

apt install npm nodejs

python3 -m pip install jupyterhub

npm install -g configurable-http-proxy

python3 -m pip install notebook

and I access using the apache server and proxy as described in the documentation of jupyterhub.

Until yesterday it worked fine, but today I have installed an upgrade of firefox (now I'm running Firefox 69.03) and now I can't execute any

notebook (python, sage or R notebooks). because I get the following error:

Opening notebook / Saving every 120 seconds / Kernel error

Failed to start the kernel / '_xsrf' argument missing from POST

Does anybody knows how to solve the issue?

Thanks in advance.