[Typo3] Warning message about TemplaVoila in the FE

[Francesco di Francia]

Hi,

just today i see those messages at the top of my homepage ( site il 95% 
completed, ):

Warning: key(): Passed variable is not an array or object in 
/home/hostnetw/public_html/cms/typo3conf/ext/templavoila/pi1/class.tx_templavoila_pi1.php 
on line 316

Warning: key(): Passed variable is not an array or object in 
/home/hostnetw/public_html/cms/typo3conf/ext/templavoila/class.tx_templavoila_htmlmarkup.php 
on line 525

Warning: Cannot modify header information - headers already sent by 
(output started at 
/home/hostnetw/public_html/forum/includes/class_core.php:2957) in 
/home/hostnetw/typo3_src-3.8.1/typo3/sysext/cms/tslib/class.tslib_fe.php 
on line 2614

If i refresh, the messages disappear. They appear only at the firs url 
call of the homepage (  url: 
http://www.netwargamingitalia.net/cms/index.php?id=10 ). If i first call 
others Urls the messages don't appear.
This issue appeared after, today, i added a content ( as a normal editor 
)  in a FCE of the homepage. You see the FCE in the homepage named as IN 
EVIDENZA.

I use typo3 3.8.1 and TV 0.4.0.
About the message related to the subfolder /forum i have an integration 
of vbulletin in typo3.

Is it an already known issue ? There's a way to avoid showing the warning ?

Regards,

Francesco