https://github.com/tgstation/tgstation/pull/51679 - pickup_item missing

code/datums/components/material_container.dm

@@ -105,7 +105,7 @@
 
 /// Proc specifically for inserting items, returns the amount of materials entered.
 /datum/component/material_container/proc/insert_item(obj/item/I, var/multiplier = 1, stack_amt)
-	if(!I)
+	if(QDELETED(I))
 		return FALSE
 
 	multiplier = CEILING(multiplier, 0.01)

code/modules/mining/machine_processing.dm

@@ -98,6 +98,8 @@
 		process_ore(AM)
 
 /obj/machinery/mineral/processing_unit/proc/process_ore(obj/item/stack/ore/O)
+	if(QDELETED(O))
+		return
 	var/datum/component/material_container/materials = GetComponent(/datum/component/material_container)
 	var/material_amount = materials.get_item_material_amount(O)
 	if(!materials.has_space(material_amount))

code/modules/mining/machine_redemption.dm

@@ -57,6 +57,8 @@
 		. += "<span class='notice'>The status display reads: Smelting <b>[ore_multiplier]</b> sheet(s) per piece of ore.<br>Reward point generation at <b>[point_upgrade*100]%</b>.<br>Ore pickup speed at <b>[ore_pickup_rate]</b>.</span>"
 
 /obj/machinery/mineral/ore_redemption/proc/smelt_ore(obj/item/stack/ore/O)
+	if(QDELETED(O))
+		return
 	var/datum/component/material_container/mat_container = materials.mat_container
 	if (!mat_container)
 		return

code/modules/mining/machine_stacking.dm

@@ -92,6 +92,8 @@
 	return ..()
 
 /obj/machinery/mineral/stacking_machine/HasProximity(atom/movable/AM)
+	if(QDELETED(AM))
+		return
 	if(istype(AM, /obj/item/stack/sheet) && AM.loc == get_step(src, input_dir))
 		process_sheet(AM)
 
@@ -104,6 +106,8 @@
 			return TRUE
 
 /obj/machinery/mineral/stacking_machine/proc/process_sheet(obj/item/stack/sheet/inp)
+	if(QDELETED(inp))
+		return
 	var/key = inp.merge_type
 	var/obj/item/stack/sheet/storage = stack_list[key]
 	if(!storage) //It's the first of this sheet added