How can you upgrade with a full install package??? That seems wrong to me. Did you just unpack the new files but kept the old database? If so, this is definitely wrong! Or if not, how did you apply the database changes between these versions if not doing an update?

OFF TOPIC. You don't help me…

Anyway, you belong to the joomla organization and you ignore that /administrator/components/com_admin/sql/updates/mysql/ holds all the incremental db updates??? (here for mysql, but also for postgresql)

I don’t ignore that. I asked if and how you have applied them in order to find out what went wrong.

And I am a normal volunteer like everybody here. That I belong to the Organisation on GitHub doesn’t mean I am a speaker or have any other position in the community than a volunteer unpaid contributor.

Do not know why, but I had to run twice this sql script

INSERT INTO `kl0_workflow_associations` (`item_id`, `stage_id`, `extension`)
SELECT `id`, 1, 'com_content.article' FROM `kl0_content`;

to get my articles back, while I had #__workflow_associations populated with the good data.

But the exception remains.