fix

code/modules/mob/living/living_active_block.dm

@@ -87,11 +87,11 @@
 	if(SEND_SIGNAL(src, COMSIG_LIVING_ACTIVE_BLOCK_START, I, other_items) & COMPONENT_PREVENT_BLOCK_START)
 		to_chat(src, "<span class='warning'>Something is preventing you from blocking!</span>")
 		return
-	if(!I?.can_active_block() && length(other_items))
-		I = other_items[1]
 	if(!I)
-		to_chat(src, "<span class='warning'>You can't block with your bare hands!</span>")
+		if(!length(other_items))
-		return
+			to_chat(src, "<span class='warning'>You can't block with your bare hands!</span>")
+			return
+		I = other_items[1]
 	if(!I.can_active_block())
 		to_chat(src, "<span class='warning'>[I] is either not capable of being used to actively block, or is not currently in a state that can! (Try wielding it if it's twohanded, for example.)</span>")
 		return
@@ -121,7 +121,8 @@
 		for(var/obj/item/I in held_items - held)
 			if(I.can_active_block())
 				return I
-	return held
+	else
+		return held
 
 /**
   * Proc called by keybindings to stop active blocking.

code/modules/surgery/organs/augments_arms.dm

@@ -132,6 +132,7 @@
 		"<span class='notice'>You extend [holder] from your [zone == BODY_ZONE_R_ARM ? "right" : "left"] arm.</span>",
 		"<span class='italics'>You hear a short mechanical noise.</span>")
 	playsound(get_turf(owner), 'sound/mecha/mechmove03.ogg', 50, 1)
+	return TRUE
 
 /obj/item/organ/cyberimp/arm/ui_action_click()
 	if(crit_fail || (organ_flags & ORGAN_FAILING) || (!holder && !contents.len))
@@ -289,7 +290,7 @@
 	UnregisterSignal(owner, COMSIG_LIVING_ACTIVE_BLOCK_START)
 	return ..()
 
-/obj/item/organ/cyberimp/arm/shield/proc/on_signal(datum/source, obj/item/blocking_item, list/other_items = list())
+/obj/item/organ/cyberimp/arm/shield/proc/on_signal(datum/source, obj/item/blocking_item, list/other_items)
 	if(!blocking_item)		//if they don't have something
 		var/obj/item/shield/S = locate() in contents
 		if(!Extend(S, TRUE))