--- a/mod_auto_answer_disco_info/mod_auto_answer_disco_info.lua	Wed Mar 07 20:13:48 2018 +0100
+++ b/mod_auto_answer_disco_info/mod_auto_answer_disco_info.lua	Wed Mar 07 20:15:20 2018 +0100
@@ -15,6 +15,10 @@
 	local node = query.attr.node;
 
 	local target_session = prosody.full_sessions[to];
+	if target_session == nil then
+		return;
+	end
+
 	local disco_info = target_session.caps_cache;
 	if disco_info ~= nil and (node == nil or node == disco_info.attr.node) then
 		local iq = st.reply(stanza);