DNN Site Crawler - LuceneController is disposed and cannot be used
http://www.dnnsoftware.com/forums/forumid/198/threadid/527555/scope/posts/threadpage/2 Found out our app pool is recycling every minute or so due to unrealistically low virtual memory settings, and that was causing problems. That Site Crawler seems to be used for when you use the site search functionality. However I have disabled that Site Crawler in HOST->Scheduler which we do not use, and that got rid of the error.