Error viewing articles/pages after assigning
Missing column of the contrib module indicates the corruption of the database. In your case workflow field is missing in content_moderation_state_field_data.

If this error start happening after upgrade, try running Database Update (either by going to /update.php or running drush updb command).

There is a Unofficial content_moderation 8.2.x to 8.3.0 upgrade path which can also help. It has relevant patches for content_moderation module with update hooks, which will migrate the tables accordingly.

Otherwise you'll have to reinstall the module, so its tables are re-created from scratch.