You can return to your default unit specification at any time, by Loading either of the default .ubg files:
MIKEZero_Default_Units.ubg
MIKEZero_US_Units.ubg
which are found in the
C:\Program Files\Common Files\DHI\MIKEZero\
directory.
Note! If you want to save any of your model specific changes, then you should first save the MIKEZero.ubg to a new name.