Add a check for lack of datacore

code/modules/mob/living/silicon/silicon.dm

@@ -174,6 +174,9 @@
 // this function displays the stations manifest in a separate window
 /mob/living/silicon/proc/show_station_manifest()
 	var/dat = "<div align='center'>"
+	if(!data_core)
+		to_chat(src,"<span class='notice'>There is no data to form a manifest with. Contact your Nanotrasen administrator.</span>")
+		return
 	dat += data_core.get_manifest(1) //The 1 makes it monochrome.
 
 	var/datum/browser/popup = new(src, "Crew Manifest", "Crew Manifest", 370, 420, src)