Set up Checkout and install a new instance as of this commit: 9b8555f Enable: allowcategorythemes allowcoursethemes allowuserthemes Create 2 courses in the category Miscellaneous Course A with setting to force the theme to afterburner Course B not forcing the theme Edit the category Miscellaneous and force the theme to anomaly Edit your users settings and set the theme to arialist In the theme selector set: Default to binarius Legacy to boxxie Mobile to brick Tablet to formal_white Set a customcss in the settings for Afterburner and Anomaly Checkout the latest integration master Download theme_brick, and theme_anomaly from Moodle.org and restore them in the theme directory mdk download theme_brick mdk download theme_anomaly Upgrade Proceed with the upgrade process As a guest, make sure the front page is using Clean Login as the user used during Set up Make sure that: Course A is using Clean Course B is using Anomaly The front page is using Clean Go to the theme selector, make sure that Default, Legacy and Tablet are using Clean Mobile is using brick Make sure the customcss for Anomaly hasn't changed Download and restore the themes afterburner, arialist and binarius Make sure the customcss for Afterburner is as it was before Make sure : Course A is now displaying Afterburner The front page when logged in is Arialist The front page as guest is still Clean Repeat the whole test, but this time checkout the latest 2.6 stable in Set up