RESOLUTION
Plesk supports Apache::ASP scripting based on Perl language, see for more information http://www.apache-asp.org.Make sure that the script you are trying to run is written on Perl but not VBScript.
JScript or VBScript scripts do not work on Apache. The special application, for example "Chili!Soft ASP" is required: http://www.apache-asp.org/faq.html#VBScript%20or%2007fa600d.
Additionally you can test Apache ASP work with simple scripts that are located in 'test' directory in newly created domain. The links to these scripts are available from the default domain page (index.html) that is installed by Plesk during domain creation.
Additional information
Simple script example:<%
$Response->Write("Hello that's test ASP script")
%>