Attempt a browser-based install with dev-tools open and network tab preserving log. Make sure that the cache is not disabled Search in the results for boost *Confirm that the CSS is fetched from styles.php (not styles_debug.php ) Confirm that it has a revision number Confirm that the revision number does not change between steps After installation view some pages in Moodle Confirm that the themerev is new, but does not change between pages Purge caches and view some more pages Confirm that the themerev is new, but does not change between pages Enable theme designer mode and view any page Find the CSS fetch in the net tab Confirm that the themerev was -1 and the file was loaded from styles_debug.php Disable theme designer mode and navigate around the site Take note of the theme revision Bump the site version.php Hit the admin page (you should get the upgrade page) For each page on the navigation: Confirm that the themerev was still the same