I just installed MediaWiki 1.18.1 (from 1.17.1) and am getting this error when I hit any page: "CACHE_ACCEL requested but no suitable object cache is present. You may want to install APC." We run eAccelerator 0.9.6.1 and it worked perfectly in this configuration with 1.17.1. CACHE_ACCEL is documented as working with eAccelerator at http://www.mediawiki.org/wiki/$wgMainCacheType. Setting $wgMainCacheType = CACHE_NONE makes the site run correctly. Any ideas why MediaWiki isn't detecting eAccelerator after the update? Backtrace: #0 [internal function]: ObjectCache::newAccelerator(Array) #1 /var/www/html/w/includes/objectcache/ObjectCache.php(62): call_user_func('ObjectCache::ne...', Array) #2 /var/www/html/w/includes/objectcache/ObjectCache.php(50): ObjectCache::newFromParams(Array) #3 /var/www/html/w/includes/objectcache/ObjectCache.php(23): ObjectCache::newFromId(3) #4 /var/www/html/w/includes/GlobalFunctions.php(3600): ObjectCache::getInstance(3) #5 /var/www/html/w/includes/Setup.php(402): wfGetMainCache() #6 /var/www/html/w/includes/WebStart.php(157): require_once('/var/www/html/w...') #7 /var/www/html/w/index.php(53): require('/var/www/html/w...') #8 {main} Thanks, DanB