diff --git a/html/index.js b/html/index.js
index d332016..18732ee 100644
--- a/html/index.js
+++ b/html/index.js
@@ -288,6 +288,7 @@ async function clickCount() {
 	}
 	
 	worker.onerror = function(evt) {
+		window.alert('An unknown error occurred while counting the votes. More details may be available in the browser\'s developer console.');
 		throw evt;
 	}