Normal for new Properties to generate Unhandled Exceptions?

Hi, I just added a new property called UseComplications which is a Boolean. In ERA, I'm seeing Unhandled Exceptions at the mUseComplications = Properties.getValue("UseComplications") line. This is the code around it. It's within a onSettingsChanged function.

		if (mHasGarminWeather == true) { // Using the Garmin Weather stuff
			ReadWeather(false);
		}	

		// Reread our complications if we're allowed
		mUseComplications = Properties.getValue("UseComplications");
		if (Toybox has :Complications) {
			// First we drop all our subscriptions before building a new list
			Complications.unsubscribeFromAllUpdates();
			// We listen for complications if we're allowed
			Complications.registerComplicationChangeCallback(mUseComplications ? self.method(:onComplicationUpdated) : null);
		}

And this is how it's defined:

<property id="UseComplications" type="boolean">false</property>

Being a new property for an existing watch face, is it "normal" for it to generate errors? Are we expected to initialize any new properties before their first use?

Thanks