This error could mean exactly what it says: an internal error that is unexpected and therefore has no meaningful error message.
If only a specific page shows this error, it can mean that your page is loading so slowly that we are running into a timeout. This is often caused not by the webpage itself, but by non-responsive ads, web-counters or broken third-party-includes. On ipinfo.info
you will find tools that show graphically which page element is not loading in time.
This internal error message could also mean that your page is causing a crash in IE. Most often this happens with XHTML strict dtds and IE6, which is a known IE flaw that has never been completely fixed by Microsoft
. Such a page will most likely cause a crash in the browsers of your visitors also.
Sometimes these IE crashes are so severe that the associated windows processes cannot be automatically killed in Netrenderer. If your webpage causes multiple consecutive occurrences of these unrecoverable crashes, you will be automatically blocked in order to prevent a complete lockup.