The bottom box on this screen:

User-added image

was added several years ago. By default the value was checked off. Since most people do not use the upfront minimum fee, it was decided to change the default setting to an unchecked state.
At the same time the default was changed, the value of the box was also added to the Defaults. 

If a customer has saved Defaults prior to this change, when loading the defaults during the admin fee process they will possibly countertenor this message box:
User-added image
There is no harm in clicking OK on the box and continuing to run your admin fee calculation.

However, you should take the time to open defaults, load each setting and click save.  Repeat for each saved default.  This will save the unchecked box in the saved default settings and you will not encounter further errors.