I upgraded my sites from 2.6 to 2.8, forgetting to grab the theme plugins. The first site I upgraded appeared okay except with the lost of a few icon graphic (like self-enrol beside a course) until I choose Clean theme. After database is updated, there is ZERO graphics, no matter what theme I then choose. I tried other theme e.g. Afterburner for 2.8 and Anomality for 2.7, manual installed with no luck. I also tried to install plugins from within the site to install Anomaility, it said successful but there is still no graphic, no css or js effect at all.
Same thing happened two other sites (which have different themes) I upgraded at the same time. They all run on same database. No change in site's URL, physical path or moodledata location.
I read that theme for 2.7 should work for 2.8. But my question is that even the Clean theme isn't work.
Besides, if my users have different theme chosen at course level, what would happen to their theme if I disallow lower level theme setting after upgrade?