When attempting to open an attachment, or document registry entry, you may get the error 404 - File not found.

Error - 404 - File not found when opening document, attachment or document registry item.

First you need to ensure that the document exists. The easiest way to do this is to also try opening the file in the author client. In most cases, if the document does not open in the author client either, the document likely does not exist.

If you are certain that the document exists, but are still encountering this issue in the web, it is possible that you have an extended ASCII character in the file name. An extended ASCII character is anything that is not a basic ASCII character, this includes, but is not limited to, characters with accents on them, for example " ö " is an extended ASCII character.

When you click on the link for the document, the file name is passed to the URL (or address bar) where it is requested by your web server. If you do not have a suitable language pack installed on your IIS server, it may not be able to correctly understand the extended ASCII character. The solution to this, is either to ensure that an appropriate language pack is installed, or to remove the character(s) from the file name,