I confirm error 1048 Column 'created_date' cannot be null in update process from rc3 to rc4.

But Joomla is successfully updated and show version Joomla rc4.

I confirm error 1048 Column 'created_date' cannot be null in update process from rc3 to rc4.

But Joomla is successfully updated and show version Joomla rc4.

@Bond97 What was the last SQL statement logged in the administrator/logs/joomla_update.php log file?

Update: I just see there has not been any additional update SQL from RC 3 to RC 4, so it can't have been a problem with update SQL scripts for this update. Maybe something went wrong with a previous update?

It just happened to me too,
The administrator/logs/joomla_update.php looks fine

#Fields: datetime	priority clientip	category	message
2021-07-16T22:33:04+00:00	INFO 10.0.2.2	update	Update started by user xxx. Old version is ‎4.0.0-rc3.
2021-07-16T22:33:06+00:00	INFO 10.0.2.2	update	Downloading update file from https://github-releases.githubusercontent.com/2464908/c405c38d-f0bc-4353-9c16-9429302683ad?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWNJYAX4CSVEH53A%2F20210716%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20210716T223305Z&X-Amz-Expires=300&X-Amz-Signature=2aad08e37d92fc0073b2ea94211cc364419759d926c5f8c4e7a68bde56db3916&X-Amz-SignedHeaders=host&actor_id=0&key_id=0&repo_id=2464908&response-content-disposition=attachment%3B%20filename%3DJoomla_4.0.0-rc4-Release_Candidate-Update_Package.zip&response-content-type=application%2Foctet-stream.
2021-07-16T22:34:27+00:00	INFO 10.0.2.2	update	File c405c38d-f0bc-4353-9c16-9429302683ad downloaded.
2021-07-16T22:34:27+00:00	INFO 10.0.2.2	update	Starting installation of new version.
2021-07-16T22:35:59+00:00	INFO 10.0.2.2	update	Finalising installation.
2021-07-16T22:35:59+00:00	INFO 10.0.2.2	update	Deleting removed files and folders.
2021-07-16T22:36:02+00:00	INFO 10.0.2.2	update	Cleaning up after installation.

Yes, there was no SQL update between RC 3 and RC 4, I had forgotten about that.

Maybe there is some 3rd party extension trying to insert or update records in one of the core tables explicitly using a NULL value on a database column where NULL is not allowed?