URL upgrade step test You are kindly asked to perform an upgrade to the patched version twice. Once with having the setting "MathJax URL" set to a non-default value, once with the default value. Note the default value, before upgrade, is https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js . Before upgrading to the patched version, check the value of "MathJax URL" (filter_mathjaxloader | httpsurl) in the administration. TEST: If the site has had the value customized to a non-default value (even changing the protocol to non-https should do), it must not change during the upgrade. TEST: If the site has been using the default value, it should change to the new default value during the upgrade. Usage step of the new version TEST: Follow https://docs.moodle.org/en/MathJax_filter and check that the filter still works, e.g. by attempting to try and render a formula written in TeX notation. See https://docs.moodle.org/33/en/Using_TeX_Notation for examples. Accessibility extension problem test As was discovered by Damyon, the new version 2.7.2 causes JS failures when any accessibility extension is enabled. To avoid the issue, there is an upgrade step that changes the default configuration so that the accessibility extensions are not loaded. Please test that when upgrading from previous default configuration, the new default configuration is set when the previous configuration was amended, it is not touched switching to the new default configuration fixes the JS problem reported by Damyon here