I've tried to set up an new template, edit an existing one to create a new email campaign, save one I've just created ...

Using Joomla 4.2, TinyMCE ...
Seems to work with Dnd editor ... but that makes things almost impossible for the user community with a totally different interface ...

All save, etc but crash with

An error has occurred.
0 Attempt to assign property "joomlaBrokeItInAMinorRelease" on array
Call stack

Function Location

1 () JROOT/libraries/vendor/joomla/registry/src/Registry.php:766
2 Joomla\Registry\Registry->bindData() JROOT/libraries/vendor/joomla/registry/src/Registry.php:761
3 Joomla\Registry\Registry->bindData() JROOT/libraries/vendor/joomla/registry/src/Registry.php:761
4 Joomla\Registry\Registry->bindData() JROOT/libraries/vendor/joomla/registry/src/Registry.php:278
5 Joomla\Registry\Registry->loadArray() JROOT/libraries/src/Editor/Editor.php:298
6 Joomla\CMS\Editor\Editor->_loadEditor() JROOT/libraries/src/Editor/Editor.php:170
7 Joomla\CMS\Editor\Editor->display() JROOT/administrator/components/com_acym/helpers/editor.php:149
8 AcyMailing\Helpers\EditorHelper->displayJoomla() JROOT/administrator/components/com_acym/helpers/editor.php:75
9 AcyMailing\Helpers\EditorHelper->display() JROOT/administrator/components/com_acym/views/mails/tmpl/edit.php:41
10 include() JROOT/administrator/components/com_acym/libraries/view.php:105
11 AcyMailing\Libraries\acymView->display() JROOT/administrator/components/com_acym/libraries/controller.php:203
12 AcyMailing\Libraries\acymController->display() JROOT/administrator/components/com_acym/controllers/mails.php:437
13 AcyMailing\Controllers\MailsController->edit() JROOT/administrator/components/com_acym/libraries/controller.php:101
14 AcyMailing\Libraries\acymController->call() JROOT/administrator/components/com_acym/acym.php:71
15 require_once() JROOT/libraries/src/Dispatcher/LegacyComponentDispatcher.php:71
16 Joomla\CMS\Dispatcher\LegacyComponentDispatcher::Joomla\CMS\Dispatcher{closure}() JROOT/libraries/src/Dispatcher/LegacyComponentDispatcher.php:73
17 Joomla\CMS\Dispatcher\LegacyComponentDispatcher->dispatch() JROOT/libraries/src/Component/ComponentHelper.php:355
18 Joomla\CMS\Component\ComponentHelper::renderComponent() JROOT/libraries/src/Application/AdministratorApplication.php:143
19 Joomla\CMS\Application\AdministratorApplication->dispatch() JROOT/libraries/src/Application/AdministratorApplication.php:186
20 Joomla\CMS\Application\AdministratorApplication->doExecute() JROOT/libraries/src/Application/CMSApplication.php:294
21 Joomla\CMS\Application\CMSApplication->execute() JROOT/administrator/includes/app.php:61
22 require_once() JROOT/administrator/index.php:32