Go to Webadmin> Administration> Configuration> WebAdmin Settings and scroll to the section titled WebAdmin Login Settings. Check off Web Server Error Logging Disabled and Submit the changes.
Restart the Policy Server by going to Webadmin> Administration> Services> Services Tab and clicking Restart.
Note: Disabling the Web Server logging stops 404, 403 and 500 Web Server Error messages from going into the WebAdmin Log. These error messages are still recorded in the