1. Message delivery status indication. https://doc.livehelperchat.com/docs/chat/#message-delivery-status-indication
2. Old chats will show messages as undelivered. Or you can execute query from update file.
3. This time it's recommended to run queries from `update_298.sql` to avoid database locks. If you have small db it's not necessary to do that. Make sure you know what you are doing.

For update just follow standard update procedure. For manual update it's update_298.sql