Platform: Windows, UniserverZ 11, ActivePerl.
I use several directories for cgi. In each of them there is a .htaccess file with two lines: Options +ExecCGI and AddHandler cgi-script .pl .cgi .exe.
The Perl programs start with #!perl.
Starting the server with UniController.exe, Perl programs run properly.
Starting the server as a service using UniService.exe, I get error 500.
For error 500, the Apache log reports /dir1/dir2/.../someprogram.pl was not found.
Running as service I can solve the problem using absolute address for perl.exe, for example, #!C:/UniServerZ/core/perl/bin/perl.exe.
I'm thinking of the possibilities:
 This is a bug of the service or
 That's right, but I have not found documentation about or
 I'm missing something.
Thank you for the answers.