403 Forbidden or No Permission to Access

This type of error is occurred due to permissions or .htaccess error.

Permissions:

The 403 Forbidden error means that your file has bad permissions. Directories and folders must be 755. Executable scripts within the cgi-bin folder must be 755. Images, media, and text files like HTML should be 755 or 644.

Hidden files (dot files):

If you see "client denied by server configuration" in your Error Logs, then this usually means bad file permissions, but could also mean that the visitor is trying to look at a hidden file, like the .htaccess file. You cannot look at that file in your browser, or any file name that starts with a dot.
e.g. http://domain.com/.htaccess will always result in a 403 error.