After transferring tables from one site to another i get this error message
JUser: :_load: Unable to load user with ID: 428
I don't know how to solve this
Hi Bebrona,
user id 428 does not exists in your joomla installation. You have to set the correct user in "Created by" field of book then save it.
You can also manually fix it via phpMyAdmin
I did this when transferring from the old version, manually