FIX: Exceptions in visualizers when controls are not present (#818).

Author: Rene Damm

Assets/Samples/Visualizers/InputControlVisualizer.cs

@@ -281,7 +281,7 @@ private static void OnEvent(InputEventPtr eventPtr, InputDevice device)
             for (var i = 0; i < s_EnabledInstances.Count; ++i)
             {
                 var component = s_EnabledInstances[i];
-                if (component.m_Control.device != device || component.m_Visualizer == null)
+                if (component.m_Control?.device != device || component.m_Visualizer == null)
                     continue;
 
                 component.OnEventImpl(eventPtr);

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -11,6 +11,8 @@ however, it has to be formatted properly to pass verification tests.
 
 ### Fixed
 
+- Exceptions in scenes of `Visualizers` sample if respective device was not present on system (e.g. in `PenVisualizer` if no pen was present in system).
+
 #### Actions
 
 - Setting timeouts from `IInputInteraction.Process` not working as expected when processing happened in response to previous timeout expiring (#714).