(BUG) The fee field on stations accepts an empty input

• It is possible to set an empty input on the stations fees tab

• When trying to “save”, it will display this message:

  

• and when saving, it will trigger this error message:

  

It shouldn’t be possible to set it to zero. I suggest changing the tab to have a binary checkbox “Collect fees?” Yes/No that unlocks a slider from 1 to 100 for setting the fees.

That would also make it clear that the maximum fee collection per minute is 100.