NPE in "method AlexaOff" when switching off a Lutron dimmer

I got this in logs from a Lutron dimmer device after switching it off (I don't have anything "Alexa related" in my setup):
java.lang.NullPointerException: Cannot invoke method off() on null object on line 304 (method AlexaOff)

Anyone one else seen this?

User error - ignore me; this was actually a group of (Lutron) dimmers, which I mistakenly created as a group of bubs while migrating from C4.