Hi Tarcisio,
First of all, thanks for your answer!
I search for a answer in OJS Upgrade failed 2.4.8-1 to 3.0.0 - #10 by tiyok but what James suggested I don’t know how to apply. In my database there are some section_id with NULL value, but I don’t know which relationship the section_id has with other fields to change to a valid value.
Best Regards,