If you have directory indexing off, and is having this problem, it's probably because the try_files you are using has a directory option:
location / {
try_files $uri $uri/ /index.html index.php;
} ^ that is the issue
Remove it and it should work:
location / {
try_files $uri /index.html index.php;
}
TL;DR: This is caused because nginx will try to index the directory, and be blocked by itself. Throwing the error mentioned by OP.
try_files $uri $uri/
means, from the root directory, try the file pointed by the uri
, if that does not exists, try a directory instead (hence the /
). When nginx access a directory, it tries to index it and return the list of files inside it to the browser/client, however by default directory indexing is disabled, and so it returns the error "Nginx 403 error: directory index of [folder] is forbidden".
Directory indexing is controlled by the autoindex
option: https://nginx.org/en/docs/http/ngx_http_autoindex_module.html