diff --git a/light9/effect/effecteval2.py b/light9/effect/effecteval2.py
--- a/light9/effect/effecteval2.py
+++ b/light9/effect/effecteval2.py
@@ -92,6 +92,9 @@ class EffectEval2:
         for arg in c.funcArgs:
             if arg.annotation == DeviceSettings:
                 v = c.devSettings
+                if v is None: # asked for ds but we have none
+                    log.debug("%s asked for devs but we have none in config", self.uri)
+                    return DeviceSettings(self.graph, [])
             elif arg.name == 'songTime':
                 v = songTime
             else: