Over the last month I have been hung up 4 times a web interface Zimbra. No people can connect to. Login page is displayed, but after entering the user name and password, the message "Loading" and nothing else happens. Most often this occurs on a Monday morning between 06:00 am and 8:30 am. When hovering web interface mail continues to be delivered through the mail clients. In crontab no jobs that could prevent or cause a crash. The logs also Zimbr there is no data. Java Logs are empty. Does anyone faced with such a situation? Where to look for the source of the problem?