When I access logmein website to remote into one of my computer, that computer shows "in session" already. Also, when I physical go to the that remote computer (host) it's locked. Does this mean someone has accessed the host computer remotely and did not log out properly? If so, I how do I unlocked so I can access host from host?
Open the Dashboard rather than Remote Control.
Go to Preferences, and Advanced. Click View Reboot Options.
Click Restart LogMeIn.
This will not restart the computer, only LogMeIn - and doing so will disconnect any existing sessions - including yours. Give it a minute to restart the service and then reconnect to the computer.