The reasons the Deep Freeze Administrator prompts for a One Time Password are:
Something has changed on the computer and Deep Freeze has noticed a change. It could be hardware or software but it has affected Deep Freeze and for security reasons the DF Administrator needs to be unlocked with a one time password and it displays a Token number for generating the One Time Password.
Open the Deep Freeze Console
Go to Tools>One Time Passwords
Type in the Token number generated by the Deep Freeze Administrator in the blank space on the left side
Click the Generate button in the middle and a One Time Password will show in the blank spot n the right side
Enter that password in the space available back in the Deep Freeze Administrator
This should unlock it if it fails it most likely needs a reinstall see Reason number 2 below.
Something within the Deep Freezer Administrator has become corrupt and even generating a One time password from the Console will not unlock it.
Reinstall the Deep Freeze Administrator using the same customization code that you used for th eintiatl isntallation of Deep Freeze Enterprise