403 errors on our files

403 means, that you don't have permission to read a file. This can happen, if the server is wrongly configured, so you should contact your server host, and ask them to fix it! Usually the answer will be, that in PHP you can set up with what permissions those files should be created, which is true, but it's a wrong way to do it, since if the server is configured correctly, the owner, who ran the PHP code has to be the owner of the created file too. This means, he has to be able to read the file, even if the file was created with 600 permissions, which should be enough, or if they would be created with 644 permissions, which is more than enough in some cases. So we cannot and shouldn't decide what permission to give, because it can be different from the necessary one, and it has to be configured on your server!

Simple test

Write this code into a PHP file:

<?php
if(file_exists('test.txt')){
    unlink(dirname(__FILE__).'/test.txt');
}
file_put_contents('test.txt','test');
echo '<iframe src="test.txt" style="width:100%;height:100%;"></iframe>';

Put it into your website's ftp somewhere, and then check it in your browser:

http://example.com/test/check.php

If you see 403 error, you have this problem.

If you would have any .htaccess file on your server, you could try removing or renaming it, and see if the errors are still present. It can be that something is not correct with your .htaccess file.