Although there are other things that can cause this error, one that we see frequently is becuase of include file paths being wrong. The most sense that we can make out of it is this: IIS is not case-sensitive, but the Vignette web server plugin is.

So, if you have an include file like: /includes/footer.asp, but in your code you reference /Includes/footer.asp, you will cause a 404. Notice the "I" is capitalized in the second example. This DOES make a difference in Vignette because of the web server plugin being case-sensitive.

Remember when you first make a new project (directory) in Vignette that it writes out to the DM as well as the ASP Docroot. If you use an uppercase letter in your name you MUST reference the file EXACTLY the way it is named.

A good habit to get into is to just use all lower case when naming paths. That way there is no confusion.