The problem should be also caused by setting of the server. E.g. the firewall can filter the loopback if the php file try to access the local file using absolute URL.

I too have the same problem. This is the error:

Warning: Call-time pass-by-reference has been deprecated in /home/content/85/8527885/html/administrator/components/com_virtuemart/classes/vmeticket_download.php on line 210
TCPDF ERROR: Some data has already been output, can't send PDF file


Yes I have allow downloadable products turned on under Virtumart / Admin / Configuration / Downloads. Also I have set the ean_codes file and children to 777. Still get the same error. Any ideas?

Hello,

Try to limit the error reporting of PHP scripts. You can do it in Joomla administrator -> global configuration -> server -> Error Reporting. Switch it to "none". If it doesn't help, it should be changed in server configuration.
Generally, it's not good to display error messages to users.

OK but that never solved the problem. I am setting up E10 and cannot get a PDF printed nor can I add a Artio button with out an internal server error. I reported this last thurs. I have set up another eticket program in the meantime but do hope I can get Artio working.