diff --git a/src/js/DefaultRules.js b/src/js/DefaultRules.js
index b21524e992bd719351262ac3eb06a7b14dd26f73..e892f502bc52e55f7b5c880806a6545c140f1e6b 100644
--- a/src/js/DefaultRules.js
+++ b/src/js/DefaultRules.js
@@ -3178,7 +3178,7 @@ globalThis.DefaultRules = function(slave) {
 		r += "<br>";
 		if (origin) {
 			if (_.isArray(origin)) {
-				origin = removeDuplicates(origin);
+				origin = removeDuplicates(origin.filter(v => !!v));
 			}
 			r += `[${origin}] `;
 		} else {