Error while running event Noxys_Waterfill::on_player_cursor_stack_changed (ID 29)
Given value has to be larger than or equal to: 0
stack traceback:
Noxys_Waterfill/control.lua:63: in function <Noxys_Waterfill/control.lua:51>

As soon as I pick up either of the waterfill items, this happens. Ideas anyone?

hhmm I'm not entirely sure how this happened unless you have another mod adjusting your reach distance somewhat dynamically.

Either way next release (0.0.5) should fix this.

There's a similar bug:
https://imgur.com/VZlORTV

Happens when you delete your character (https://wiki.factorio.com/console#Enable_god_mode, "/c game.player.character=nil"), and then try to grab waterfill.

Fixed that one too in 0.0.7.