Describe the bug

A clear and concise description of what the issue is.

To Reproduce

Provide a link to a live example, or an unambiguous set of steps to reproduce this issue. Include configuration, logs, etc. to reproduce, if relevant.

1. assigning a custom var of Type array to a host like in this example the exampleuser : vars : { Number_of_Linux_Cores: 2, OS: "Linux", notify_users: [ "exampleuser" ], teams_notifications: "enabled" }
2. click this host in Icingaweb2 and observe /var/log/icingaweb2/icingaweb2.log
3. exception below is produced

###########################
2025-02-12T13:43:53+01:00 - ERROR - TypeError in /usr/share/icingaweb2/modules/director/library/Director/ProvidedHook/Icingadb/CustomVarRenderer.php:256 with message: Illegal offset type in isset or empty
#0 /usr/share/icingaweb2/modules/icingadb/library/Icingadb/Hook/CustomVarRendererHook.php(85): Icinga\Module\Director\ProvidedHook\Icingadb\CustomVarRenderer->renderCustomVarValue()
Icinga/icingaweb2#1 [internal function]: Icinga\Module\Icingadb\Hook\CustomVarRendererHook::Icinga\Module\Icingadb\Hook{closure}()
Icinga/icingaweb2#2 /usr/share/icingaweb2/modules/icingadb/library/Icingadb/Widget/Detail/CustomVarTable.php(104): call_user_func()
Icinga/icingaweb2#3 /usr/share/icingaweb2/modules/icingadb/library/Icingadb/Widget/Detail/CustomVarTable.php(252): Icinga\Module\Icingadb\Widget\Detail\CustomVarTable->renderVar()
Icinga/icingaweb2#4 /usr/share/icinga-php/ipl/vendor/ipl/html/src/HtmlDocument.php(344): Icinga\Module\Icingadb\Widget\Detail\CustomVarTable->assemble()
Icinga/icingaweb2#5 /usr/share/icinga-php/ipl/vendor/ipl/html/src/HtmlDocument.php(566): ipl\Html\HtmlDocument->ensureAssembled()
Icinga/icingaweb2#6 /usr/share/icinga-php/ipl/vendor/ipl/html/src/HtmlDocument.php(390): ipl\Html\HtmlDocument->render()
Icinga/icingaweb2#7 /usr/share/icinga-php/ipl/vendor/ipl/html/src/BaseHtmlElement.php(297): ipl\Html\HtmlDocument->renderUnwrapped()
Icinga/icingaweb2#8 /usr/share/icinga-php/ipl/vendor/ipl/html/src/BaseHtmlElement.php(365): ipl\Html\BaseHtmlElement->renderContent()
Icinga/icingaweb2#9 /usr/share/icinga-php/ipl/vendor/ipl/html/src/HtmlDocument.php(568): ipl\Html\BaseHtmlElement->renderUnwrapped()
Icinga/icingaweb2#10 /usr/share/icinga-php/ipl/vendor/ipl/html/src/HtmlDocument.php(390): ipl\Html\HtmlDocument->render()
Icinga/icingaweb2#11 /usr/share/icinga-php/ipl/vendor/ipl/html/src/BaseHtmlElement.php(297): ipl\Html\HtmlDocument->renderUnwrapped()
Icinga/icingaweb2#12 /usr/share/icinga-php/ipl/vendor/ipl/html/src/BaseHtmlElement.php(365): ipl\Html\BaseHtmlElement->renderContent()
Icinga/icingaweb2#13 /usr/share/icinga-php/ipl/vendor/ipl/html/src/HtmlDocument.php(568): ipl\Html\BaseHtmlElement->renderUnwrapped()
Icinga/icingaweb2#14 /usr/share/icinga-php/ipl/vendor/ipl/html/src/HtmlDocument.php(390): ipl\Html\HtmlDocument->render()
Icinga/icingaweb2#15 /usr/share/icinga-php/ipl/vendor/ipl/html/src/BaseHtmlElement.php(297): ipl\Html\HtmlDocument->renderUnwrapped()
Icinga/icingaweb2#16 /usr/share/icinga-php/ipl/vendor/ipl/html/src/BaseHtmlElement.php(365): ipl\Html\BaseHtmlElement->renderContent()
Icinga/icingaweb2#17 /usr/share/icinga-php/ipl/vendor/ipl/html/src/HtmlDocument.php(568): ipl\Html\BaseHtmlElement->renderUnwrapped()
Icinga/icingaweb2#18 /usr/share/icinga-php/ipl/vendor/ipl/html/src/HtmlDocument.php(390): ipl\Html\HtmlDocument->render()
Icinga/icingaweb2#19 /usr/share/icinga-php/ipl/vendor/ipl/html/src/HtmlDocument.php(568): ipl\Html\HtmlDocument->renderUnwrapped()
Icinga/icingaweb2#20 /usr/share/icinga-php/ipl/vendor/ipl/web/src/Compat/ViewRenderer.php(62): ipl\Html\HtmlDocument->render()
Icinga/icingaweb2#21 /usr/share/icinga-php/vendor/vendor/shardj/zf1-future/library/Zend/Controller/Action/Helper/ViewRenderer.php(970): ipl\Web\Compat\ViewRenderer->render()
Icinga/icingaweb2#22 /usr/share/icinga-php/vendor/vendor/shardj/zf1-future/library/Zend/Controller/Action/HelperBroker.php(277): Zend_Controller_Action_Helper_ViewRenderer->postDispatch()
Icinga/icingaweb2#23 /usr/share/icingaweb2/modules/icingadb/library/Icingadb/Web/Controller.php(484): Zend_Controller_Action_HelperBroker->notifyPostDispatch()
Icinga/icingaweb2#24 /usr/share/php/Icinga/Web/Controller/Dispatcher.php(76): Icinga\Module\Icingadb\Web\Controller->dispatch()
Icinga/icingaweb2#25 /usr/share/icinga-php/vendor/vendor/shardj/zf1-future/library/Zend/Controller/Front.php(954): Icinga\Web\Controller\Dispatcher->dispatch()
Icinga/icingaweb2#26 /usr/share/php/Icinga/Application/Web.php(294): Zend_Controller_Front->dispatch()
Icinga/icingaweb2#27 /usr/share/php/Icinga/Application/webrouter.php(105): Icinga\Application\Web->dispatch()
Icinga/icingaweb2#28 /usr/share/icingaweb2/public/index.php(4): require_once('...')
Icinga/icingaweb2#29 {main}
###########################

Expected behavior

no exception

Screenshots

If applicable, add screenshots to help explain your problem.

Your Environment

Include as many relevant details about the environment you experienced the problem in

• Icinga Web 2 version and modules (System - About): 2.12.2
• Web browser used: Edge Browser
• Icinga 2 version used : r2.14.5-1
• PHP version used (php --version): 8.1.2-1ubuntu2.20
• Server operating system and version: Ubuntu 22.04.5 LTS

Additional context

Add any other context about the problem here.