Warning: Unknown(somephpfile.php): failed to open stream: Permission denied in Unknown on line 0.
I wonder who writes error messages for the PHP development team. Some state-of-the art professional or a poet!! Only he can understand what this error means.
When my php script threw the same message, I looked into the file permissions of this file and saw that it had only read/execute permissions for the owner. This error disappeared when I gave permissions for Group and Everyone.
(Note: There are different kinds of Permission denied error in PHP. Your problem might not be due to this reason. However, it doesn’t hurt to look into the permissions of the corresponding file. If you think that I could help, please leave a note here.)