Can't add new categories

Hello,

For some reason i can't seem to add new categories to my site. It was working fine and then suddenly, when i tried to add a new category, i got the following:

Forbidden
You don't have permission to access /shop/admin/categories.php on this server.

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

Is this something to worry about? I never changed anything and didn't even do anything in the admin folder. I was just in admin adding categories when this happened.

Thank you

Has your hosting site changed versions of php or anything else on the server?

If you look at categories.php file date is it the same as the others or changed?