EdCast is using OpenEdX to host Quizzes and in the last week one of our major clients faced a production issue in a Quiz where the Final Check button was not clickable for many users.
Upon investigation we found the below:
MathJax, a library used by EDX, (https://cdn.mathjax.org/mathjax/2.7-latest/MathJax.js), has shut down its CDN. So it's redirecting the users to the new CDN. But it's not a simple HTTPS redirect. The script removes the original script element on the page, and then replaces it with the new script tag with the new url (using replaceNode).
Will need to change the URL inside of EDX and re-deploy EDX. This is the file that needs editing: https://github.com/Course-Master/edx-platform-cm/blob/50df8766d51575d811fc61fb86817efb5962f70f/common/templates/mathjax_include.html
Upon further investigation we found that this change for done by a third party component which edX used.
We have deployed the new changes on our end however our client was blocked on this and affected their business.
I am sure every client who is using OpenedX and has Quizzes hosted through it must have faced an issue.
In future can we try and provide some indication of an interim change like these?