The mod Filter Helper (0.1.7) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event FilterHelper::on_gui_opened (ID 88)
FilterHelper/control.lua:268: attempt to concatenate field 'name' (a nil value)
stack traceback:
FilterHelper/control.lua:268: in function 'add_items_circuit'
FilterHelper/control.lua:285: in function 'add_items'
FilterHelper/control.lua:309: in function <FilterHelper/control.lua:302>

Fixed by wrapping line 268:
if signal.signal.name then
items[signal.signal.name] = signal.signal.type .. "/" .. signal.signal.name
end

Fixed in 0.1.8