Can open page but cannot edit text in page

Hi,

A client has a problem with editing pages in the editor. A page can be opened but cannot be edited and changed,
The error seen in the left hand corner of Zeta Producer (version is:

Server Error in '/' Application.
The resource cannot be found.
[font='&quot']Description: [/font][font='&quot']HTTP
404. The resource you are looking for (or one of its dependencies)
could have been removed, had its name changed, or is temporarily
unavailable. Please review the following URL and make sure that it is
spelled correctly.

[/font][font='&quot']Requested URL: [/font][font='&quot']/latest-news-desktop-inline.html[/font]

Have you any idea what that can be?

Thanks very much!

Marion Vegter