I've had this problem for a while. I've tried everything I can find to no avail.
I've got the file system (linux, cPanel) set up using root htaccess directives for sub domains. Everything works accept "blocked"
With main domain 403 it works as expected. Sub domains, all built on WP, I get the following.
deny from env=blocked
allow from all
It seems it's trying (Additionally...) to use a custom error document, which is what I'd prefer, but being denied, since it's a page. The first part of the response is the server's standard 403 response.
I don't want to use the "ErrorDocument 403 /403.shtml" since that's results in a redirect. Right now I have no ErrorDocument code in root but 403.shtml in root gets served. I put a 403.shtml file in subdomain but you see the result is the same.
I'm lacking knowledge somewhere in this. So I need to ask for the fix. Thanks