The 403 Forbidden error is an HTTP status code that means that accessing the page or resource you were trying to reach is absolutely forbidden for some reason.
Check for errors in the URL. The most common reason for a 403 Forbidden error is because the URL was typed wrong or the link that was clicked on points to a URL with some kind of mistake in it.
If you're sure the page you're trying to reach is correct, the 403 Forbidden error message may be a mistake. At this point it's probably in your best interest to contact the webmaster or other website contact and inform them of the problem.