diff -r 4ce38f21f4cd -r cff680298793 launcher/fx/src/main/java/org/apidesign/bck2brwsr/launcher/fximpl/Console.java
--- a/launcher/fx/src/main/java/org/apidesign/bck2brwsr/launcher/fximpl/Console.java	Tue Jan 26 04:36:23 2016 +0100
+++ b/launcher/fx/src/main/java/org/apidesign/bck2brwsr/launcher/fximpl/Console.java	Mon Apr 18 07:32:35 2016 +0200
@@ -39,7 +39,10 @@
     @JavaScriptBody(args = { "elem", "attr" }, body = "return elem[attr].toString();")
     private static native Object getAttr(Object elem, String attr);
 
-    @JavaScriptBody(args = { "id", "attr", "value" }, body = "window.document.getElementById(id)[attr] = value;")
+    @JavaScriptBody(args = { "id", "attr", "value" }, body = "\n"
+        + "var e = window.document.getElementById(id);\n"
+        + "if (e) e[attr] = value;\n"
+    )
     private static native void setAttr(String id, String attr, Object value);
 
     @JavaScriptBody(args = { "elem", "attr", "value" }, body = "elem[attr] = value;")