JEM does not store imported events

Unfortunately, there is a JEM error when I want to save a given event in JEM:
can anyone see what has happened here? How does JEM work (again)?

An error has now occurred when saving an event:
0 Call to a member function format() on falseCall Stack
# Function Location
1 () JROOT/libraries/src/Form/Field/:405
2 Joomla\CMS\Form\Field\CalendarField->filter() JROOT/libraries/src/Form/:1058
3 Joomla\CMS\Form\Form->filter() JROOT/libraries/src/Form/:1002
4 Joomla\CMS\Form\Form->process() JROOT/libraries/src/MVC/Model/:219
5 Joomla\CMS\MVC\Model\FormModel->validate() JROOT/libraries/src/MVC/Controller/:636
6 Joomla\CMS\MVC\Controller\FormController->save() JROOT/libraries/src/MVC/Controller/:730
7 Joomla\CMS\MVC\Controller\BaseController->execute() JROOT/administrator/components/com_jem/:53
8 require_once() JROOT/libraries/src/Dispatcher/:71
9 Joomla\CMS\Dispatcher\LegacyComponentDispatcher::{closure:Joomla\CMS\Dispatcher\LegacyComponentDispatcher::dispatch():70}() JROOT/libraries/src/Dispatcher/:73
10 Joomla\CMS\Dispatcher\LegacyComponentDispatcher->dispatch() JROOT/libraries/src/Component/:361
11 Joomla\CMS\Component\ComponentHelper::renderComponent() JROOT/libraries/src/Application/:150
12 Joomla\CMS\Application\AdministratorApplication->dispatch() JROOT/libraries/src/Application/:205
13 Joomla\CMS\Application\AdministratorApplication->doExecute() JROOT/libraries/src/Application/:304
14 Joomla\CMS\Application\CMSApplication->execute() JROOT/administrator/includes/:58
15 require_once() JROOT/administrator/:32


The same thing sometimes happens with venue:
When saving for the first time:
Save failed. Error: Incorrect datetime value: ‘now’ for column `d001ca38`.`j5_jem_venues`.`created` at row 1
Then save again immediately:
The entry has been saved.



JEM Paket: 4.3.4, Joomla 5.3.4, PHP: 8.4.7. Events: 1200

This problem does not occur with newly entered events that have not been imported.

I have already repaired and released the J!-database, but there has been no improvement.
What might be the cause of the error? How can I fix it?

best regards, m.

How do you import an event where from. There are some new fields. Best is to export an event to gwt the right fields. The event, 0 venues you want to import must corresond.

How do you import an event where from. There are some new fields. Best is to export an event to gwt the right fields. The event, 0 venues you want to import must correspond.