Server path does not exist. Ensure variable $_SERVER['DOCUMENT_ROOT'] is set correctly

[GoogleCodeExporter]

Hi, after installation of Timthumb on a server, ( with cache folder and correct 
permissions , as specified on 
http://www.binarymoon.co.uk/2010/11/timthumb-hints-tips/ and documentation ) 
this one still don't want to display the picture. No problem on a local 
installation with Xampp, or on another server. 

I get this specific error : 
>> A TimThumb error has occured
>> The following error(s) occured:
>> * Server path does not exist. Ensure variable $_SERVER['DOCUMENT_ROOT'] is 
set correctly
>> * Could not find the internal image you specified.

link : 
http://manujarvinen.com/~secret/testing/Artwork-Web-Folder-master_new/lib/timthu
mb.php?src=http://manujarvinen.com/~secret/testing/Artwork-Web-Folder-master_new
/01_concept-art_demo-picture.jpg&w=1100

'internal image' link is active ( 
http://manujarvinen.com/~secret/testing/Artwork-Web-Folder-master_new/01_concept
-art_demo-picture.jpg ), 
Any hint how this could be solved, and what should I try ? How to set correctly 
$_SERVER['DOCUMENT_ROOT'] ? Is it the real issue ? Thanks! 

Timthumb version : last SVN , and also tested with an older 2.8.11

Original issue reported on code.google.com by davidre...@gmail.com on 16 Sep 2014 at 12:10