Error creating InteractiveVideo when Vimeo is activated in the plugin config

[mhilbert]

After fixing the PHP 8.0 problems I get the following error when trying to create a new InteractiveVideo object (tested with ILIAS 8.9, InteractiveVideo 3.5.2 and PHP 8.0.30):

Whoops\Exception\ErrorException thrown with message "Trying to access array offset on value of type null"

Stacktrace:
#14 Whoops\Exception\ErrorException in /path/to/htdocs/ilias/Customizing/global/plugins/Services/Repository/RepositoryObject/InteractiveVideo/VideoSources/plugin/InteractiveVideoVimeo/class.ilInteractiveVideoVimeo.php:57
#13 ilErrorHandling:handlePreWhoops in /path/to/htdocs/ilias/Customizing/global/plugins/Services/Repository/RepositoryObject/InteractiveVideo/VideoSources/plugin/InteractiveVideoVimeo/class.ilInteractiveVideoVimeo.php:57
#12 ilInteractiveVideoVimeo:doReadVideoSource in /path/to/htdocs/ilias/Customizing/global/plugins/Services/Repository/RepositoryObject/InteractiveVideo/VideoSources/plugin/InteractiveVideoVimeo/class.ilInteractiveVideoVimeoGUI.php:22
#11 ilInteractiveVideoVimeoGUI:getForm in /path/to/htdocs/ilias/Customizing/global/plugins/Services/Repository/RepositoryObject/InteractiveVideo/classes/class.ilObjInteractiveVideoGUI.php:1504
#10 ilObjInteractiveVideoGUI:appendFormsFromFactory in /path/to/htdocs/ilias/Customizing/global/plugins/Services/Repository/RepositoryObject/InteractiveVideo/classes/class.ilObjInteractiveVideoGUI.php:985
#9 ilObjInteractiveVideoGUI:initCreateForm in /path/to/htdocs/ilias/Customizing/global/plugins/Services/Repository/RepositoryObject/InteractiveVideo/classes/class.ilObjInteractiveVideoGUI.php:971
#8 ilObjInteractiveVideoGUI:initCreationForms in /path/to/htdocs/ilias/Services/Object/classes/class.ilObjectGUI.php:618
#7 ilObjectGUI:createObject in /path/to/htdocs/ilias/Services/Object/classes/class.ilObject2GUI.php:618
#6 ilObject2GUI:create in /path/to/htdocs/ilias/Services/Repository/PluginSlot/class.ilObjectPluginGUI.php:163
#5 ilObjectPluginGUI:executeCommand in /path/to/htdocs/ilias/Services/UICore/classes/class.ilCtrl.php:199
#4 ilCtrl:forwardCommand in /path/to/htdocs/ilias/Services/Repository/classes/class.ilRepositoryGUI.php:243
#3 ilRepositoryGUI:show in /path/to/htdocs/ilias/Services/Repository/classes/class.ilRepositoryGUI.php:223
#2 ilRepositoryGUI:executeCommand in /path/to/htdocs/ilias/Services/UICore/classes/class.ilCtrl.php:199
#1 ilCtrl:forwardCommand in /path/to/htdocs/ilias/Services/UICore/classes/class.ilCtrl.php:174
#0 ilCtrl:callBaseClass in /path/to/htdocs/ilias/ilias.php:24