Fixing Jupyter access denied on Ubuntu 22.04

After the upgrade to Ubuntu 22.04 Jupyter Notebook (on Firefox 99.0.1) would greet me with an Access Denied error. Not exactly conducive to work.

I tried setting access right of the directories (I also thought about access issues given that .local is a hidden directory), but it turns out that creating an explicit configuration helps:

jupyter notebook --generate-config

This creates a file at: ~/.jupyter/jupyter_notebook_config.py

and in this (text) file we’re looking for c.NotebookApp.use_redirect_file, uncomment it, and set it to

c.NotebookApp.use_redirect_file = False

(as explained in the comments; this seems completely fine on a single-user machine).

Jitsi on GNU/Linux

We’re currently using Jitsi a lot, an open-source video conferencing solution. On my GNU/Linux machine running Ubuntu, I had issues with using it on Firefox, using up all the CPU and blocking/freezing after a while. Solution: it works fine on Chromium.

Yoshikoder won’t start on Ubuntu

Two days ago my Yoshikoder refused to start on the Ubuntu (GNU/Linux) machine. So I tried in the console java -jar Yoshikoder-0.6.4.jar and was informed that “Error: Assistive Technology not found: org.GNOME.Accessibility.AtkWrapper”. A quick on the web look turned out that the solution is simple. In the console, I opened the following file:

sudo leafpad /etc/java-11-openjdk/accessibility.properties

and commented out the line causing problems (in my case it was the last line), so that it reads:

#assistive_technologies=org.GNOME.Accessibility.AtkWrapper

Sorted.

Zotero on Ubuntu Does Not Update: How to Fix the Permissions

My Zotero did not update, showing a dialog that while there is an update available, I apparently lacked the permissions to update. First I tried to chmod the directory where I extracted Zotero to, and the Zotero binary, but that did not change the error message. It turns out there is another directory that needs to be changed:

sudo chmod 707 /usr/bin/zotero && sudo chmod -R 707 /opt/zotero

(in the terminal) and now everything works as it should.

Update 10 April 2019: see comments for a more appropriate handling of the permissions.