Add article - ERROR 404

I have set up my page in the back end as a new single article.

I have added this to the main menu which is on the left hand side of my site

www.cater-data.co.uk

When you click the link it says there is an eror 404.

The only thing i can see that may be causing this is that i get a script error -i.e. there is a script running on this page do you want to stop it? Could this be causing the problem?

Im not sure what to do?

Kind regards
Emma

Problem solved - I think it is where i didnt put a category in - changing it to uncategorized seems to have resolved the erorr.