should do this instead

code/game/gamemodes/clock_cult/clock_cult.dm

@@ -151,8 +151,8 @@ Credit where due:
 	var/datum/team/clockcult/main_clockcult
 
 /datum/game_mode/clockwork_cult/pre_setup() //Gamemode and job code is pain. Have fun codediving all of that stuff, whoever works on this next - Delta
-	var/list/errorList = list()
-	load_reebe(errorList)
+	if(!load_reebe())
+		return FALSE
 	if(CONFIG_GET(flag/protect_roles_from_antagonist))
 		restricted_jobs += protected_jobs
 	if(CONFIG_GET(flag/protect_assistant_from_antagonist))

code/modules/antagonists/clockcult/clockcult.dm

@@ -242,11 +242,10 @@
 	return "<div class='panel clockborder'>[parts.Join("<br>")]</div>"
 
 //I have no idea where to put this so I'm leaving it here. Loads reebe. Only one reebe can exist, so it's checked via a global var.
-/proc/load_reebe(list/errorList)
+/proc/load_reebe()
 	if(GLOB.reebe_loaded)
 		return
-	if(!errorList)
-		errorList = list()
+	var/list/errorList = list()
 	var/list/reebes = SSmapping.LoadGroup(errorList, "Reebe", "map_files/generic", "City_of_Cogs.dmm", default_traits = ZTRAITS_REEBE, silent = TRUE)
 	if(errorList.len)	// reebe failed to load
 		message_admins("Reebe failed to load!")