ERR_CONTENT_LENGTH_MISMATCH when loading video in chrome - php

Question

So I get this error when some of the video plays. When Chrome completely downloads the video, it stops playing with this error. Also the status of the request changes from 206 to (failed) and then Chrome sends some other requests with Range:bytes=2990775- and the server response is:
Accept-Ranges:bytes
Cache-Control:private
Connection:keep-alive
Content-Disposition:attachment; filename="About The Author.mp4"
Content-Length:0
Content-Range:bytes 2990775-2990775/2990776
Content-Transfer-Encoding:binary
Content-Type:video/mp4
Date:Tue, 14 Feb 2017 13:46:24 GMT
Last-Modified:Wed, 08 Feb 2017 05:43:27 GMT
Pragma:public
Server:Apache/2
Vary:User-Agent
X-Powered-By:PHP/5.4.45
I have another website on the same server and it works fine there.
Here is my PHP code:
$filesize = filesize($resource->path);
$matches = explode("-", substr($_SERVER['HTTP_RANGE'],6));
if (empty($matches[1]))
{
$matches[1] = $filesize - 1;
}
$offset = intval($matches[0]);
$length = intval($matches[1]) - $offset;
$file = fopen($resource->path, 'r');
fseek($file, $offset);
$data = fread($file, $length);
fclose($file);
header('HTTP/1.1 206 Partial Content');
header('Content-Range: bytes ' . $offset . '-' . ($offset + $length) . '/' . $filesize);
header('Pragma: public');
header('Last-Modified: '.gmdate ('D, d M Y H:i:s', filemtime ($resource->path)).' GMT');
header('Cache-Control: private',false);
header('Content-Type: ' . $mime);
header('Content-Length: ' . ($length + 1));
header('Content-Disposition: attachment; filename="' . $resource->filename . '"');
header('Content-Transfer-Encoding: binary');
header('Accept-Ranges: bytes');
print($data);
Sorry for my bad english.

Answer 1

I've found the problem.
I changed $data = fread($file, $length); to $data = fread($file, $length + 1);.
I don't know why the requested length should be plus one but it solve'd the problem.