- Hold down shift and reload the page. Doing a shift-reload doesn't just reload the page, it reloads all of the dependencies as well. Since MathJax has moved since the previous version this will clear your cache of old MathJax files.
- Make sure that you have installed the new version of MathJax. This is handled by the "npm install" step in the upgrade instructions. If this has been run successfully, then you should see a mathjax directory in /opt/webwork/webwork2/htdocs/node_modules
- If these don't solve the problem, then the next step would be to look at your browser's error console (usually under developer tools). Any errors there might help diagnose the problem.