After upgrading t3 bs3 blank template J3 to J4, I got 500 error when I click the edit button to update the page from front end following login.
The version of t3 bs3 blank template is 3.0.2 and t3 framework version is 3.1.3.
According to the log below ,edit.php might cause 500 error.
The error happens only when I try to edit from front end. No error in Cassiopeia case.
I suspect it may be t3 bs3 J4 bug. If so, please develop the fix immediately.
Thanks in advance, T.Sejimo

Following is
the log displayed

500 - behavior::tabstate not found.
You may not be able to visit this page because of:

an out-of-date bookmark/favourite
a search engine that has an out-of-date listing for this site
a mistyped address
you have no access to this page
The requested resource was not found.
An error has occurred while processing your request.
Please try one of the following pages:

Home Page
If difficulties persist, please contact the website administrator and report the error below.

behavior::tabstate not found.
/home/wghp/www/wghp07/smcc-tajima/libraries/src/HTML/HTMLHelper.php:141

Call stack

Function Location

1 () JROOT/libraries/src/HTML/HTMLHelper.php:141
2 Joomla\CMS\HTML\HTMLHelper::_() JROOT/plugins/system/t3/base-bs3/html/com_content/form/edit.php:12
3 include() JROOT/plugins/system/t3/includes/core/t3.php(528) : eval()'d code:410
4 Joomla\CMS\MVC\View_JHtmlView->loadTemplate() JROOT/plugins/system/t3/includes/core/t3.php(528) : eval()'d code:203
5 Joomla\CMS\MVC\View_JHtmlView->display() JROOT/components/com_content/src/View/Form/HtmlView.php:197
6 Joomla\Component\Content\Site\View\Form\HtmlView->display() JROOT/libraries/src/MVC/Controller/BaseController.php:645
7 Joomla\CMS\MVC\Controller\BaseController->display() JROOT/components/com_content/src/Controller/DisplayController.php:121
8 Joomla\Component\Content\Site\Controller\DisplayController->display() JROOT/libraries/src/MVC/Controller/BaseController.php:678
9 Joomla\CMS\MVC\Controller\BaseController->execute() JROOT/libraries/src/Dispatcher/ComponentDispatcher.php:143
10 Joomla\CMS\Dispatcher\ComponentDispatcher->dispatch() JROOT/components/com_content/src/Dispatcher/Dispatcher.php:56
11 Joomla\Component\Content\Site\Dispatcher\Dispatcher->dispatch() JROOT/libraries/src/Component/ComponentHelper.php:361
12 Joomla\CMS\Component\ComponentHelper::renderComponent() JROOT/libraries/src/Application/SiteApplication.php:208
13 Joomla\CMS\Application\SiteApplication->dispatch() JROOT/libraries/src/Application/SiteApplication.php:249
14 Joomla\CMS\Application\SiteApplication->doExecute() JROOT/libraries/src/Application/CMSApplication.php:293
15 Joomla\CMS\Application\CMSApplication->execute() JROOT/includes/app.php:61
16 require_once() JROOT/index.php:32