my site’s drupal version is 6.19 . there are always logs like the following.
the recent log entries shows
“type: page not found
location:http://www.example.com/display.html
referrer:
message:500.shtml
severity: warning
“
the above’s log is generated by when an anonymous accessed the url,but the page ( http://www.example.com/display.html ) content is exist and can access by authenticated user .when i clear the cache. the anonymous can access that page. why and how to find out which reason maybe cause this. thank you.
This is most likely caused by robots accessing your site, or users refreshing the page after they have been logged out.
I really would not worry about these messages in your logs, they can safely be ignored.