When trying to remove armor equipment the game errors and comments it is extra bobs.
Disabling extra bobs allows removing equipment from the grid.
https://www.dropbox.com/s/jshpzaynobx1r4g/error%20extrabobs2.png?dl=0

Looks like the useful_equipment.lua might have some player references left behind?

Error Useful_equipment\Useful_equipment.lua
Line 46-47
function(event)
local character = game.characters[event.character_index]

Yeah, it probably has. Gonna clean that up until the weekend. Thanks for the report.

Thanks for all your work by the way.
Sorry that clean up after their change is such a big pain.