I made a configuration change to my SharePoint 2010 Web Application (earlier question) that enabled Anonymous access and now my site returns 404 errors!? Even when I change the setting back it does not resolve the error. To make matters worse now my Central Admin site returns the same 404 error. Looking at the source for the 404 error page I see an HttpError...CheckSuspiciousPhysicalPath.
Any ideas on how to debug this would be great.