Your device may enter the "lockout" mode if too many incorrect passcode attempts have been made within a certain amount of time.
This security feature prevents potential intruders from guessing your passcode by trying every possible combination ("brute force" guessing). The lockout time is exponentially increased as more unsuccessful attempts are made, making this approach too time consuming to be worth the effort.
If you find that your Felik is in lockout mode that requires you to wait too long, you can simply unplug the power, wait a few seconds, then plug Felik back in. Once booted up, it will no longer be in lockout mode.