Problems with Links – dont open

Hi,

We need help, we still have problems with the theme.

When we click the main menu, dont open the pages. That happen also with others page or others items in the main page or links to text.

When we click in any link, appear:
Not Found
The requested URL /oferta/ was not found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Help Please!!!!!

Thanks.