There are several broken features in this software that really need to be addressed. I have noticed in this case that emails are not being sent to staff OR users after the initial ticket is created. I have tested this with changing the priority as well as department transferred. Both have email confirmations enabled in the configuration and it keeps generating a system error saying You must provide at least one recipient email address. Since email is a REQUIRED field there is always an email and it is my personal email that I am testing with. I have verified the email is correct. There seems to be an issue where if USER is disabled Admin nor Staff can get emails either. This is a serious communication issue in the coding. There are some areas the user does not need to see such as Overdue. I would want staff to see it is overdue and to check the ticket but not the user.

Broke Completely:
Marked In Progress (no error but no email sent either though is showing in the templates)

Works (provided USER email is Enabled): -- These should still send to staff when User is set to Disabled in Configurations but they do not.
Reply Ticket
Response Ticket
Close Ticket
Mark Overdue
Change Priority
Delete Ticket
Lock
Unlock
Department Transfer

Kind of Works:
Assign Ticket. Email is sent but {STAFF_MEMBER_TITLE} is apparently a bad parameter because the email reply looks like this:
Sucess: Ticket Reassign (btw... it is Success not Sucess)

Ticket Subject : Test

Your ticket has been successfully reassigned! Ticket ID:cGVD9gqTk is reassigned to Staff Member: {STAFF_MEMBER_TITLE}