ERROR: Can't find or cannot load modules:

Open up plexum_task.pl and edit line 47, un-comment it and replace the server path in;

use lib qw('/usr/localhost/cgi-bin/ /usr/localhost/cgi-bin/PlexumAPIs/');

or

use lib qw('/usr/localhost/cgi-bin /usr/localhost/cgi-bin/PlexumAPIs');