Dear all,
I've just upgraded my homepage https://www.hedgehogs-garden.de to joomla 4 and now I've this error message:
500behavior::tooltip not found.
It appears the page you were looking for doesn't exist. Sorry about that.

The respective callstack is:
Fields: datetime priority clientip category message
2023-03-12T21:33:38+00:00 CRITICAL 84.162.213.207 error Uncaught Throwable of type InvalidArgumentException thrown with message "behavior::tooltip not found.". Stack trace: #0 [ROOT]/templates/gk_musicstate/html/com_content/category/blog_item.php(11): Joomla\CMS\HTML\HTMLHelper::_('jhtml.behavior....')
#1 [ROOT]/libraries/src/MVC/View/HtmlView.php(410): include('/hp/ab/ag/tu/ww...')
#2 [ROOT]/templates/gk_musicstate/html/com_content/category/blog.php(107): Joomla\CMS\MVC\View\HtmlView->loadTemplate(NULL)
#3 [ROOT]/libraries/src/MVC/View/HtmlView.php(410): include('/hp/ab/ag/tu/ww...')
#4 [ROOT]/libraries/src/MVC/View/HtmlView.php(203): Joomla\CMS\MVC\View\HtmlView->loadTemplate(NULL)
#5 [ROOT]/libraries/src/MVC/View/CategoryView.php(262): Joomla\CMS\MVC\View\HtmlView->display(NULL)
#6 [ROOT]/components/com_content/src/View/Category/HtmlView.php(182): Joomla\CMS\MVC\View\CategoryView->display(NULL)
#7 [ROOT]/libraries/src/Cache/Controller/ViewController.php(102): Joomla\Component\Content\Site\View\Category\HtmlView->display()
#8 [ROOT]/libraries/src/MVC/Controller/BaseController.php(634): Joomla\CMS\Cache\Controller\ViewController->get(Object(Joomla\Component\Content\Site\View\Category\HtmlView), 'display')
#9 [ROOT]/components/com_content/src/Controller/DisplayController.php(121): Joomla\CMS\MVC\Controller\BaseController->display(true, Array)
#10 [ROOT]/libraries/src/MVC/Controller/BaseController.php(672): Joomla\Component\Content\Site\Controller\DisplayController->display()
#11 [ROOT]/libraries/src/Dispatcher/ComponentDispatcher.php(143): Joomla\CMS\MVC\Controller\BaseController->execute('display')
#12 [ROOT]/components/com_content/src/Dispatcher/Dispatcher.php(56): Joomla\CMS\Dispatcher\ComponentDispatcher->dispatch()
#13 [ROOT]/libraries/src/Component/ComponentHelper.php(355): Joomla\Component\Content\Site\Dispatcher\Dispatcher->dispatch()
#14 [ROOT]/libraries/src/Application/SiteApplication.php(200): Joomla\CMS\Component\ComponentHelper::renderComponent('com_content')
#15 [ROOT]/libraries/src/Application/SiteApplication.php(241): Joomla\CMS\Application\SiteApplication->dispatch()
#16 [ROOT]/libraries/src/Application/CMSApplication.php(294): Joomla\CMS\Application\SiteApplication->doExecute()
#17 [ROOT]/includes/app.php(61): Joomla\CMS\Application\CMSApplication->execute()
#18 [ROOT]/index.php(32): require_once('/hp/ab/ag/tu/ww...')
#19 {main}

I guess it has to do with the gk_musicstate template.
See for example: https://www.hedgehogs-garden.de/index.php/bandinfo

Any idea how I can fix this? The installed template is the latest I found at your website.

Best regards
Felix