It concerns the removal of old event.
I now solve it by deleting it directly in the database.

The events that give this message when deleting do have the status -1.

If I then select to show everything from the trash, I see them.

If I remove them from there it works fine.
Only the row that belongs to it is NOT removed from the details table.

So something is going wrong somewhere.

If I select multiple events I don't get the notification and it is neatly deleted and moved to the trash

When I clicked 1 event and redirected it to the trash I got this error.

If I selected more than one, it went well.
Then all information was properly removed from the database.

If I selected 1 then I got the error, but it was put in the trash.
If I then removed it from there with only this one selected, the line in the details table was not removed.

A PHP Exception occurred on your site. Here you can find the stack trace:

Exception Type: Error
File: /plugins/actionlog/jevents/jevents.php
Line: 56
Message: Call to a member function ev_id() on null

#0 /libraries/joomla/event/event.php(70): PlgActionlogJEvents->onPublishEvent(Array, -1)
#1 libraries/joomla/event/dispatcher.php(160): JEvent->update(Array)
#2 /libraries/src/Application/BaseApplication.php(108): JEventDispatcher->trigger('onpublishevent', Array)
#3 /administrator/components/com_jevents/controllers/icalevent.php(1371): Joomla\CMS\Application\BaseApplication->triggerEvent('onPublishEvent', Array)
#4 /libraries/src/MVC/Controller/BaseController.php(702): AdminIcaleventController->delete()
#5 /administrator/components/com_jevents/jevents.php(268): Joomla\CMS\MVC\Controller\BaseController->execute('delete')
#6 /libraries/src/Component/ComponentHelper.php(402): require_once('...')
#7 /libraries/src/Component/ComponentHelper.php(377): Joomla\CMS\Component\ComponentHelper::executeComponent('...')
#8 /libraries/src/Application/AdministratorApplication.php(101): Joomla\CMS\Component\ComponentHelper::renderComponent('com_jevents')
#9 /libraries/src/Application/AdministratorApplication.php(159): Joomla\CMS\Application\AdministratorApplication->dispatch()
#10 /libraries/src/Application/CMSApplication.php(225): Joomla\CMS\Application\AdministratorApplication->doExecute()
#11 /administrator/index.php(51): Joomla\CMS\Application\CMSApplication->execute()
#12 {main}
Request information
GET variables
Array
(
)
POST variables
Array
(
[filter] => Array
(
[search] =>
[catid] =>
[showpast] => 1
[icsFile] =>
[created_by] =>
[state] =>
[access] =>
)

[list] => Array
(
[fullordering] =>
[limit] => 15
)

[cid] => Array
(
[0] => 431
)

[limitstart] => 0
[option] => com_jevents
[task] => icalevent.delete
[boxchecked] => 1
[filter_order] => starttime
[filter_order_Dir] => asc
[................] => 1
)

Can you describe step by step from the start what you are doing to create this problem - I am unable to recreate the issue.