--- a/plugins/mod_c2s.lua	Thu Mar 18 14:30:47 2021 +0100
+++ b/plugins/mod_c2s.lua	Wed Mar 17 12:47:16 2021 +0100
@@ -190,12 +190,12 @@
 				if not session.destroyed then
 					session.log("warn", "Failed to receive a stream close response, closing connection anyway...");
 					sm_destroy_session(session, reason_text);
-					conn:close();
+					if conn then conn:close(); end
 				end
 			end);
 		else
 			sm_destroy_session(session, reason_text);
-			conn:close();
+			if conn then conn:close(); end
 		end
 	else
 		local reason_text = (reason and (reason.name or reason.text or reason.condition)) or reason;