Hello, I have an really important update for this issue. Last month I installed the the "Admin Tools Application" as recommended by Ludovic Dubost. I ran the "Programming Rights Check" script and inspected the "User Rights Check" page. No right anomalies, as far as I can see. A few minutes ago, our XWiki suffered under a new, but correlating, problem. I visited our Wiki and noticed that the Wiki was rendered with the default theme and with the default header image. Furthermore, as a guest, I had the opportunity to delete spaces/documents and visit restricted areas. I inspected this issue with the Admin Tools: I checked the memory usage of our XEM: 1,5GB Free Active DB Connections: 13 of 50 Idle DB Connections: 5 of 5 After I tried the "Flush Cache" script of the "Admin Tools Application", the Wiki theme and header image was instant restored, and all rights seemed working. I have a strong guess that this issue is connected to our initial problem. I guess this problem fixed itself a couple of times after a period of time. During this period, the Wiki is exposed and the crawler can trigger undesired actions. I hope someone have an idea why our Wiki behaves like this. Greetings Jan -- View this message in context: http://xwiki.475771.n2.nabble.com/severe-trouble-with-web-crawlers-tp7442162... Sent from the XWiki- Users mailing list archive at Nabble.com.