Website saying Forbidden You don’t have permission to access this resource

Hi

I have a client site currently saying

Forbidden

You don’t have permission to access this resource.Server unable to read htaccess file, denying access to be safe

Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.

The main content is htaccess file is permissions from your plugin and general default htaccess info.

What could be causing this please? Do you have any suggestions?

Thanks