# Equations not rendering in JupyterLab 3 "MathJax is not defined"

Jupyter Lab won’t render my math equations in Latex syntax when writing them in markdown with the {equation} format.

I’m running JupyterLab from an Ubuntu remote machine and using it in a windows machine with Google Chrome.

When I check my browser console I get the ReferenceError “MathJax is not defined” as shown below. I have no idea why this is happening.

How did you install JupyterLab? And could you provide a small example? Do you encounter the same problems when you use mybinder.org?

Hey, I installed it normally with conda install -c conda forge as instructed in the documentation. When I write something like $1+2^2=5$ in a markdown cell I expect the cell to render the latex equation (1 + 2² = 5) but it shows up in plain text instead. I’m not familiar with binder but I believe my problem is likely specific to my machine or jupyter installation as I’m able to render equations when using jupyter lab from other machines just fine.

That simple example you provided should word, you are totally right. I have little idea what could have gone wrong here, but here are some working hypotheses:

Working hypothesis 1: For whatever reason, the installation on the remote machine is broken. I have no idea what are the things that could break but here you need to go back to the “IT defaults”:

• Have you tried to turn it off and on again?
• Have you tried to deinstall it cleanly (making sure to delete all the files) and then re-install it?

Because of the SyntaxError, I favor this approach.

Working hypothesis 2: The damage happens somewhere on the network route. Maybe a reverse proxy (using regex?) is going wild and accidentially inserts strings into a file where they don’t belong? Here, you might need to dig deep, i.e. check firewalls, proxies etc. how they affect your traffic. A quick check might be maybe to create an SSH tunnel to circumvent those.

I hope while traveling down one of these paths, you will find some helpful information!

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