This is why you need to be careful when copypasting

Author: Oblisk234

yogstation/code/datums/world_topic.dm

@@ -93,8 +93,8 @@ GLOBAL_VAR_INIT(mentornoot, FALSE)
 	if(!add_mhelp_query.Execute())
 		message_admins("Failed insert mhelp into mhelp DB. Check the SQL error logs for more details.")
 	qdel(add_mhelp_query)
-	if(ckey in SSYogs.mentortickets)
-		var/datum/mentorticket/T = SSYogs.mentortickets[ckey]
+	if(C.ckey in SSYogs.mentortickets)
+		var/datum/mentorticket/T = SSYogs.mentortickets[C.ckey]
 		T.log += "<b>[from]:</b> [msg]"
 	to_chat(C, "<font color='purple'>Mentor PM from-<b>[discord_mentor_link(from, from_id)]</b>: [msg]</font>", confidential = TRUE)
 	var/show_char_recip = !C.is_mentor() && CONFIG_GET(flag/mentors_mobname_only)