--- a/util/pubsub.lua	Sun Jul 01 04:42:41 2018 +0200
+++ b/util/pubsub.lua	Sun Jul 01 04:44:24 2018 +0200
@@ -293,7 +293,7 @@
 		local ok, err = save_node_to_store(self, self.nodes[node]);
 		if not ok then
 			self.nodes[node] = nil;
-			return ok, err;
+			return ok, "internal-server-error";
 		end
 	end