I use to add the following code to insert the additional field in template:

<div class="calendar-luogo">{$event.fields.Luogo}</div>

where "Luogo" is the additional field... but nothing appear on the frontend...

this is the output of {$event|print_r}

Array ( [event_id] => 325 [event_title] => Il sol ci ha dato alla testa
[event_summary] => [event_details] => [event_date_start] => 2013-11-16 21:00:00
[event_date_end] => [event_parent_id] => -1 [event_recur_period] => none
[event_date_recur_end] => [event_created_by] => -103 [event_create_date] =>
2013-09-09 18:54:29 [event_modified_date] => 2013-11-07 15:24:37
[event_recur_nevents] => -1 [event_recur_interval] => 1 [event_recur_weekdays]
=> [event_recur_monthdays] => [event_allows_overlap] => 1 [url] =>
http://www.rimbamband.it/calendario/58/325-Il-sol-ci-ha-dato-alla-testa.html
[categories] => Array ( [0] => 1 ) [category_names] => Spettacoli [fields] =>
Array ( [L] => L [3] => 3 [T] => T ) [admin_uid] => -203 [is_parent] => 1 ) 1

and in the apache_log, i see this warning:

[Thu Nov 07 15:47:22 2013] [warn] [client xxxxx] mod_fcgid: stderr: PHP Warning:
Illegal string offset 'field_name' in
xxxxxx/modules/CGCalendar/lib/class.cgc_event_loader.php on line 141, referer:
http://www.rimbamband.it/calendario.html
[Thu Nov 07 15:47:22 2013] [warn] [client xxxxx] mod_fcgid: stderr: PHP Warning:
Illegal string offset 'field_value' in
xxxxxx/modules/CGCalendar/lib/class.cgc_event_loader.php on line 141, referer:
http://www.rimbamband.it/calendario.html
[Thu Nov 07 15:47:22 2013] [warn] [client xxxxx] mod_fcgid: stderr: PHP Warning:
Illegal string offset 'field_name' in
xxxxxx/modules/CGCalendar/lib/class.cgc_event_loader.php on line 141, referer:
http://www.rimbamband.it/calendario.html
[Thu Nov 07 15:47:22 2013] [warn] [client xxxxx] mod_fcgid: stderr: PHP Warning:
Illegal string offset 'field_value' in
xxxxxx/modules/CGCalendar/lib/class.cgc_event_loader.php on line 141, referer:
http://www.rimbamband.it/calendario.html
[Thu Nov 07 15:47:22 2013] [warn] [client xxxxx] mod_fcgid: stderr: PHP Warning:
Illegal string offset 'field_name' in
xxxxxx/modules/CGCalendar/lib/class.cgc_event_loader.php on line 141, referer:
http://www.rimbamband.it/calendario.html
[Thu Nov 07 15:47:22 2013] [warn] [client xxxxx] mod_fcgid: stderr: PHP Warning:
Illegal string offset 'field_value'
inxxxxxxx/modules/CGCalendar/lib/class.cgc_event_loader.php on line 141,
referer: http://www.rimbamband.it/calendario.html
[Thu Nov 07 15:47:22 2013] [warn] [client xxxxx] mod_fcgid: stderr: PHP Notice: 
Undefined index: Luogo in
xxxxxxxx/tmp/templates_c/CGCalendar^251d3130edd7cb1dd0fc071f2df3feddc4d98ebf.module_db_tpl.CGCalendar;event_Sample.php
on line 79, referer: http://www.rimbamband.it/calendario.html

i do something wrong?

any help is appreciated

Nicola