diff --git a/light9/effect/sequencer/eval_faders.py b/light9/effect/sequencer/eval_faders.py
--- a/light9/effect/sequencer/eval_faders.py
+++ b/light9/effect/sequencer/eval_faders.py
@@ -66,11 +66,16 @@ class FaderEval:
         faderEffectOutputs: List[DeviceSettings] = []
         now = UnixTime(time.time())
         for f in self.faders:
-            if f.value is None:
-                raise TypeError('f.value should be set by now')
-            effectSettings = EffectSettings(self.graph, [(f.effect, f.setEffectAttr, f.value)])
+            try:
+                if f.value is None:
+                    log.warning(f'{f.value=}; should be set during _compile. Skipping {f.uri}')
+                    continue
+                effectSettings = EffectSettings(self.graph, [(f.effect, f.setEffectAttr, f.value)])
 
-            ds = f.ee.compute(now, effectSettings)
-            faderEffectOutputs.append(ds)
+                ds = f.ee.compute(now, effectSettings)
+                faderEffectOutputs.append(ds)
+            except Exception:
+                log.warning(f'on fader {f}')
+                raise
 
         return DeviceSettings.merge(self.graph, faderEffectOutputs)