web Create and install a 3.6.x site. For example: git checkout v3.6.0 Check out the master branch git checkout master Create any of the following files that are being detected by the patch. (e.g. on Linux, use the " touch " command): lib/form/yui/src/showadvanced/js/showadvanced.js mkdir -p lib/form/yui/src/showadvanced/js touch lib/form/yui/src/showadvanced/js/showadvanced.js lib/tests/output_external_test.php touch lib/tests/output_external_test.php message/amd/src/message_area.js touch message/amd/src/message_area.js message/templates/message_area.mustache touch message/templates/message_area.mustache question/yui/src/qbankmanager/build.json mkdir question/yui/src/qbankmanager touch question/yui/src/qbankmanager/build.json Open your Moodle instance on your browser. Log in as admin and proceed with the upgrade. Verify that a notice ("Mixed Moodle versions detected....") is displayed saying that there are problems upgrading and a proper procedure for upgrading to a major release. Delete the touched file(s) in 2. Click " Reload ". Verify that the upgrade now proceeds ok. cli Disclaimer: CLI upgrade does not run the upgrade_stale_php_files_present() check. MDL-53596 has been created about that. Nothing to test here yet.