Column not found: 1054 Unknown column 'revision.revision_user' in 'field list': after Update from 8.2 to 8.4
As per this comment, this could be related to Dynamic Entity Reference module as per this bug report.

The solution is to apply this patch or upgrade to the latest version of this module.

To fix the problem manually, you need to rename the field in the database from revision_user to revision_user_int.

Another suggestion from here says to add: $settings['update_free_access'] = TRUE; into your settings file and run /update.php to invoke the database updates again.