diff --git a/light9/live/Light9AttrControl.ts b/light9/live/Light9AttrControl.ts
--- a/light9/live/Light9AttrControl.ts
+++ b/light9/live/Light9AttrControl.ts
@@ -93,17 +93,31 @@ export class Light9AttrControl extends L
 
   private onValueProperty() {
     if (this.deviceAttrRow === null) throw new Error();
-    if (this.effect !== null && this.graph !== undefined) {
-      const p = this.effect.edit(this.deviceAttrRow.device, this.deviceAttrRow.uri, this.value);
-      if (p.adds.length || p.dels.length) {
-        log("Effect told us to graph.patch", p, "to", this.graph);
+    if (!this.graph) {
+      log('ignoring value change- no graph yet')
+      return;
+    }
+    if (this.effect === null) {
+      this.value = null;
+    } else {
+      const p = this.effect.edit(
+        //
+        this.deviceAttrRow.device,
+        this.deviceAttrRow.uri,
+        this.value
+      );
+      if (!p.isEmpty()) {
+        log("Effect told us to graph.patch this:\n", p.dump());
         this.graph.applyAndSendPatch(p);
       }
     }
   }
 
   private onEffectProperty() {
-    if (this.effect === null) throw new Error();
+    if (this.effect === null) {
+      log('no effect obj yet')
+      return;
+    }
     // effect will read graph changes on its own, but emit an event when it does
     this.effect.settingsChanged.subscribe(() => {
       this.effectSettingsChanged();