The problem happens because is_hidden column, which is used in the Legacy/Content/Location/Gateway/DoctrineDatabase::isHiddenByParent() method is not in the selection list of the query thaht fetches the data.

The problem is commented on the PR: https://github.com/ezsystems/ezpublish-kernel/pull/1528#discussion_r256697859

Steps to reproduce (2.4.1):

1. In symfony env dev.
2. Create 3 folders in Home, on under the other.
3. Go to the second, middle one and change its Visibility to hidden.
4. Go to the third, last one (which is hidden by superior / parent) and try to move it to another folder (screen 1).

Actual result: Folder is not moved, error occurs in UI "Notice: Undefined index: is_hidden" (screen 2).

Remarks: Could not reproduce in prod env. Moving the first and second folder works.