My message view is set for reading pane on the right. So emails are read on the right and on the left is a list of emails. I am using a MacBook as a computer.

Problem:
When Zimbra is restarted the program allows me to jump from message to message with an arrow key, but soon stops working unless stop and restart the program again.

I would like to find out how to continue using the arrow key to review my messages without shutting down the program and restarting it again.

Ideas?