Causes

the user made a valid request but the server is refusing to serve the request. It usually occurs :

  • when the user that is running the web server process, does not have sufficient permissions to read the file that is being accessed.

Fixes

Step 1
  • check the file’s permission settings.
Step 2
  • user can also confirm whether the system protects the file in cPanel’s Indexes interface (cPanel >> Home >> Advanced >> Indexes).