diff --git a/code/datums/diseases/transformation.dm b/code/datums/diseases/transformation.dm
index 36c7d70f3c..430b7e07b0 100644
--- a/code/datums/diseases/transformation.dm
+++ b/code/datums/diseases/transformation.dm
@@ -32,16 +32,16 @@
 	..()
 	switch(stage)
 		if(1)
-			if (prob(stage_prob) && stage1)
+			if (prob(stage_prob) && length(stage1))
 				to_chat(affected_mob, pick(stage1))
 		if(2)
-			if (prob(stage_prob) && stage2)
+			if (prob(stage_prob) && length(stage2))
 				to_chat(affected_mob, pick(stage2))
 		if(3)
-			if (prob(stage_prob*2) && stage3)
+			if (prob(stage_prob*2) && length(stage3))
 				to_chat(affected_mob, pick(stage3))
 		if(4)
-			if (prob(stage_prob*2) && stage4)
+			if (prob(stage_prob*2) && length(stage4))
 				to_chat(affected_mob, pick(stage4))
 		if(5)
 			do_disease_transformation(affected_mob)
@@ -162,7 +162,7 @@
 	desc = "This disease, actually acute nanomachine infection, converts the victim into a cyborg."
 	severity = DISEASE_SEVERITY_BIOHAZARD
 	visibility_flags = 0
-	stage1	= list()
+	stage1	= null
 	stage2	= list("Your joints feel stiff.", "<span class='danger'>Beep...boop..</span>")
 	stage3	= list("<span class='danger'>Your joints feel very stiff.</span>", "Your skin feels loose.", "<span class='danger'>You can feel something move...inside.</span>")
 	stage4	= list("<span class='danger'>Your skin feels very loose.</span>", "<span class='danger'>You can feel... something...inside you.</span>")
@@ -195,7 +195,7 @@
 	desc = "This disease changes the victim into a xenomorph."
 	severity = DISEASE_SEVERITY_BIOHAZARD
 	visibility_flags = 0
-	stage1	= list()
+	stage1	= null
 	stage2	= list("Your throat feels scratchy.", "<span class='danger'>Kill...</span>")
 	stage3	= list("<span class='danger'>Your throat feels very scratchy.</span>", "Your skin feels tight.", "<span class='danger'>You can feel something move...inside.</span>")
 	stage4	= list("<span class='danger'>Your skin feels very tight.</span>", "<span class='danger'>Your blood boils!</span>", "<span class='danger'>You can feel... something...inside you.</span>")
diff --git a/code/datums/traits/good.dm b/code/datums/traits/good.dm
index f6ac0e26af..23fd75f982 100644
--- a/code/datums/traits/good.dm
+++ b/code/datums/traits/good.dm
@@ -108,10 +108,10 @@
 	var/mob/living/carbon/human/H = quirk_holder
 	var/obj/item/choice_beacon/music/B = new(get_turf(H))
 	H.put_in_hands(B)
-	H.equip_to_slot(B, SLOT_IN_BACKPACK)
+	H.equip_to_slot_if_possible(B, SLOT_IN_BACKPACK)
 	var/obj/item/musicaltuner/musicaltuner = new(get_turf(H))
 	H.put_in_hands(musicaltuner)
-	H.equip_to_slot(musicaltuner, SLOT_IN_BACKPACK)
+	H.equip_to_slot_if_possible(musicaltuner, SLOT_IN_BACKPACK)
 	H.regenerate_icons()
 
 /datum/quirk/photographer
diff --git a/code/game/objects/items/stacks/stack.dm b/code/game/objects/items/stacks/stack.dm
index f707c02ce9..5f2795c857 100644
--- a/code/game/objects/items/stacks/stack.dm
+++ b/code/game/objects/items/stacks/stack.dm
@@ -219,8 +219,9 @@
 			O = new R.result_type(usr.drop_location())
 		if(O)
 			O.setDir(usr.dir)
+			log_craft("[O] crafted by [usr] at [loc_name(O.loc)]")
+
 		use(R.req_amount * multiplier)
-		log_craft("[O] crafted by [usr] at [loc_name(O.loc)]")
 
 		if(R.applies_mats && custom_materials && custom_materials.len)
 			var/list/used_materials = list()
diff --git a/code/game/turfs/simulated/walls.dm b/code/game/turfs/simulated/walls.dm
index d26a6efb02..268e8e9109 100644
--- a/code/game/turfs/simulated/walls.dm
+++ b/code/game/turfs/simulated/walls.dm
@@ -70,7 +70,8 @@
 
 /turf/closed/wall/proc/break_wall()
 	new sheet_type(src, sheet_amount)
-	return new girder_type(src)
+	if(girder_type)
+		return new girder_type(src)
 
 /turf/closed/wall/proc/devastate_wall()
 	new sheet_type(src, sheet_amount)
diff --git a/code/modules/mob/living/carbon/human/species.dm b/code/modules/mob/living/carbon/human/species.dm
index b428f49578..fc2817f134 100644
--- a/code/modules/mob/living/carbon/human/species.dm
+++ b/code/modules/mob/living/carbon/human/species.dm
@@ -397,7 +397,7 @@ GLOBAL_LIST_EMPTY(roundstart_race_names)
 		if(I.flags_inv & HIDEFACIALHAIR)
 			facialhair_hidden = TRUE
 
-	if(H.wear_mask)
+	if(H.wear_mask && istype(H.wear_mask))
 		var/obj/item/clothing/mask/M = H.wear_mask
 		dynamic_fhair_suffix = M.dynamic_fhair_suffix //mask > head in terms of facial hair
 		if(M.flags_inv & HIDEFACIALHAIR)
@@ -451,7 +451,7 @@ GLOBAL_LIST_EMPTY(roundstart_race_names)
 		if(I.flags_inv & HIDEHAIR)
 			hair_hidden = TRUE
 
-	if(H.wear_mask)
+	if(H.wear_mask && istype(H.wear_mask))
 		var/obj/item/clothing/mask/M = H.wear_mask
 		if(!dynamic_hair_suffix) //head > mask in terms of head hair
 			dynamic_hair_suffix = M.dynamic_hair_suffix
diff --git a/code/modules/mob/living/simple_animal/friendly/dog.dm b/code/modules/mob/living/simple_animal/friendly/dog.dm
index 4bf8aa5e23..485cece8b7 100644
--- a/code/modules/mob/living/simple_animal/friendly/dog.dm
+++ b/code/modules/mob/living/simple_animal/friendly/dog.dm
@@ -445,7 +445,7 @@
 				sleep(3)
 				step_to(src,movement_target,1)
 
-				if(movement_target)		//Not redundant due to sleeps, Item can be gone in 6 decisecomds
+				if(movement_target?.loc)		//Not redundant due to sleeps, Item can be gone in 6 decisecomds
 					if (movement_target.loc.x < src.x)
 						setDir(WEST)
 					else if (movement_target.loc.x > src.x)
diff --git a/code/modules/surgery/organs/eyes.dm b/code/modules/surgery/organs/eyes.dm
index a915d12838..6b93995e62 100644
--- a/code/modules/surgery/organs/eyes.dm
+++ b/code/modules/surgery/organs/eyes.dm
@@ -319,6 +319,8 @@
 	on_mob.forceMove(scanning)
 	for(var/i in 1 to light_beam_distance)
 		scanning = get_step(scanning, scandir)
+		if(!scanning)
+			break
 		if(scanning.opacity || scanning.has_opaque_atom)
 			stop = TRUE
 		var/obj/effect/abstract/eye_lighting/L = LAZYACCESS(eye_lighting, i)