vCloud Usage Meter 4.x
VCF Usage Meter 9.0
Following message indicates root password has expired:
"You are required to change your password immediately (password expired)".
Try logging in to respective Usage Meter appliance console from vCenter using root credential and it should allow to change the root account password.
In case if there is no option to change password, use the following knowledge to reset the password.
Resetting the vCloud Usage Meter root password.