When buyers attempt to download the ordered file they get: Internal Server Error "The server encountered an internal error or misconfiguration and was unable to complete your request".
This may occur if the server uses a CGI-Wrapper that does not support non-parsed headers. Check the server HTTP error log for the error:-
nph-dl000001.pl malformed header from script. Bad header=HTTP/1.1 200 OK:
To resolve this problem rename nph-download.pl to download.pl in the site directory on your PC and update the site ( Web | Update Website).