Error during unserialization

#0 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Helper/UnserializeArray.php(44): Unserialize_Parser->unserialize()
#1 /var/www/vhosts/infinityvision.it/public_html/app/code/community/Alma/Installments/Helper/FeePlansHelper.php(172): Mage_Core_Helper_UnserializeArray->unserialize()
#2 /var/www/vhosts/infinityvision.it/public_html/app/code/community/Alma/Installments/Helper/FeePlansHelper.php(182): Alma_Installments_Helper_FeePlansHelper->getFeePlansConfigFromBackOffice()
#3 /var/www/vhosts/infinityvision.it/public_html/app/code/community/Alma/Installments/Helper/FeePlansHelper.php(340): Alma_Installments_Helper_FeePlansHelper->getEnabledFeePlansConfigFromBackOffice()
#4 /var/www/vhosts/infinityvision.it/public_html/app/code/community/Alma/Installments/Block/ProductWidget.php(89): Alma_Installments_Helper_FeePlansHelper->getEnableFeePlansForBadge()
#5 /var/www/vhosts/infinityvision.it/public_html/app/design/frontend/base/default/template/alma/product/badge.phtml(41): Alma_Installments_Block_ProductWidget->getEnableFeePlansForBadge()
#6 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Template.php(241): include('/var/www/vhosts...')
#7 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Template.php(272): Mage_Core_Block_Template->fetchView()
#8 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Template.php(286): Mage_Core_Block_Template->renderView()
#9 /var/www/vhosts/infinityvision.it/public_html/app/code/community/Alma/Installments/Block/ProductWidget.php(51): Mage_Core_Block_Template->_toHtml()
#10 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Abstract.php(923): Alma_Installments_Block_ProductWidget->_toHtml()
#11 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Text/List.php(43): Mage_Core_Block_Abstract->toHtml()
#12 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Abstract.php(923): Mage_Core_Block_Text_List->_toHtml()
#13 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Abstract.php(641): Mage_Core_Block_Abstract->toHtml()
#14 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Abstract.php(585): Mage_Core_Block_Abstract->_getChildHtml()
#15 /var/www/vhosts/infinityvision.it/public_html/app/design/frontend/smartwave/porto/template/catalog/product/view.phtml(243): Mage_Core_Block_Abstract->getChildHtml()
#16 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Template.php(241): include('/var/www/vhosts...')
#17 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Template.php(272): Mage_Core_Block_Template->fetchView()
#18 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Template.php(286): Mage_Core_Block_Template->renderView()
#19 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Abstract.php(923): Mage_Core_Block_Template->_toHtml()
#20 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Text/List.php(43): Mage_Core_Block_Abstract->toHtml()
#21 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Abstract.php(923): Mage_Core_Block_Text_List->_toHtml()
#22 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Abstract.php(641): Mage_Core_Block_Abstract->toHtml()
#23 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Abstract.php(585): Mage_Core_Block_Abstract->_getChildHtml()
#24 /var/www/vhosts/infinityvision.it/public_html/app/design/frontend/smartwave/porto/template/page/1column.phtml(49): Mage_Core_Block_Abstract->getChildHtml()
#25 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Template.php(241): include('/var/www/vhosts...')
#26 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Template.php(272): Mage_Core_Block_Template->fetchView()
#27 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Template.php(286): Mage_Core_Block_Template->renderView()
#28 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Block/Abstract.php(923): Mage_Core_Block_Template->_toHtml()
#29 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Model/Layout.php(555): Mage_Core_Block_Abstract->toHtml()
#30 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(390): Mage_Core_Model_Layout->getOutput()
#31 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Cms/Helper/Page.php(137): Mage_Core_Controller_Varien_Action->renderLayout()
#32 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Cms/Helper/Page.php(52): Mage_Cms_Helper_Page->_renderPage()
#33 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Cms/controllers/IndexController.php(75): Mage_Cms_Helper_Page->renderPage()
#34 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Cms_IndexController->noRouteAction()
#35 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch()
#36 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match()
#37 /var/www/vhosts/infinityvision.it/public_html/app/code/core/Mage/Core/Model/App.php(365): Mage_Core_Controller_Varien_Front->dispatch()
#38 /var/www/vhosts/infinityvision.it/public_html/app/Mage.php(683): Mage_Core_Model_App->run()
#39 /var/www/vhosts/infinityvision.it/public_html/index.php(14): Mage::run()
#40 {main}