In drupal, keep getting an upgrade message all over site from htmlpurifier that a 4.0 is available. Ran upgrades (uploaded files and ran update.php) but still have message. No finds on this when I googled around.
Supposedly a flush.php in a maintenace folder will flush it's cache (which is invconveniently separate from the rest of Drupal's cache), but trying to execute in browser gets me an error.
Either upgrade is bad or needs cache flushed, or just shut off this message. Advice?