Further runtime fixes by AnturK.

code/modules/mob/living/carbon/human/death.dm

@@ -44,7 +44,8 @@
 		if(M.occupant == src)
 			M.go_out()
 
-	dna.species.spec_death(gibbed, src)
+	if(!QDELETED(dna)) //The gibbed param is bit redundant here since dna won't exist at this point if they got deleted.
+		dna.species.spec_death(gibbed, src)
 
 	if(SSticker.HasRoundStarted())
 		SSblackbox.ReportDeath(src)

code/modules/mob/living/carbon/human/species_types/jellypeople.dm

@@ -849,6 +849,8 @@
 	linked_mobs.Add(M)
 	if(!selflink)
 		to_chat(M, "<span class='notice'>You are now connected to [slimelink_owner.real_name]'s Slime Link.</span>")
+		RegisterSignal(M, COMSIG_MOB_DEATH , .proc/unlink_mob)
+		RegisterSignal(M, COMSIG_PARENT_QDELETING, .proc/unlink_mob)
 	var/datum/action/innate/linked_speech/action = new(src)
 	linked_actions.Add(action)
 	action.Grant(M)
@@ -858,6 +860,7 @@
 	var/link_id = linked_mobs.Find(M)
 	if(!(link_id))
 		return
+	UnregisterSignal(M, list(COMSIG_MOB_DEATH, COMSIG_PARENT_QDELETING))
 	var/datum/action/innate/linked_speech/action = linked_actions[link_id]
 	action.Remove(M)
 	to_chat(M, "<span class='notice'>You are no longer connected to [slimelink_owner.real_name]'s Slime Link.</span>")
@@ -890,18 +893,11 @@
 		Remove(H)
 		return
 
-	if(QDELETED(H) || H.stat == DEAD)
-		species.unlink_mob(H)
-		return
-
 	if(message)
 		var/msg = "<i><font color=#008CA2>\[[species.slimelink_owner.real_name]'s Slime Link\] <b>[H]:</b> [message]</font></i>"
 		log_directed_talk(H, species.slimelink_owner, msg, LOG_SAY, "slime link")
 		for(var/X in species.linked_mobs)
 			var/mob/living/M = X
-			if(QDELETED(M) || M.stat == DEAD)
-				species.unlink_mob(M)
-				continue
 			to_chat(M, msg)
 
 		for(var/X in GLOB.dead_mob_list)