I managed to solve it in another way,
This is the original code from the generator:
<?php echo JDom::_('html.fly.file', array(
'altKey' => 'alias',
'attrs' => array('center','format:png'),
'dataKey' => 'logo',
'dataObject' => $row,
'height' => 145,
'indirect' => true,
'root' => '[DIR_FIRMY_LOGO]',
'route' => array('view' => 'firma','layout' => 'wizytowka','cid[]' => $row->id),
'titleKey' => 'nazwa_firmy',
'tooltip' => true,
'width' => 195
));?>
and after modification:
<?php echo JDom::_('html.fly.file', array(
'alt' => 'alias',
'attrs' => array('center','format:png'),
'dataKey' => 'logo',
'dataObject' => $row,
'height' => 145,
'indirect' => true,
'root' => '[DIR_FIRMY_LOGO]',
'route' => array('view' => 'firma','layout' => 'wizytowka','cid[]' => $row->id),
'title' => 'nazwa_firmy',
'tooltip' => true,
'width' => 195
));?>
Here is what has been modified:
'altKey' => 'alias',
to
'alt' => 'alias',
and
'titleKey' => 'nazwa_firmy',
to
'title' => 'nazwa_firmy',
and it also works