Implicit "Horizontal" Axis exceptions?

I have a project where I am taking input from a gamepad, using both sticks. One stick is for movement, and the other stick is for gunlaying. I have programmed custom-named axes in the InputManager to control these inputs, and they work fine.

My project compiles, but I receive a constant stream of exceptions at runtime -

ArgumentException: Input Axis Horizontal is not setup.
 To change the input settings use: Edit -> Project Settings -> Input
UnityEngine.EventSystems.StandaloneInputModule.ShouldActivateModule () (at C:/buildslave/unity/build/Extensions/guisystem/guisystem/EventSystem/InputModules/StandaloneInputModule.cs:120)
UnityEngine.EventSystems.EventSystem.Update () (at C:/buildslave/unity/build/Extensions/guisystem/guisystem/EventSystem/EventSystem.cs:234)

I believe this to be related to the default EventSystem added to the project by virtue of the UI canvas I have added for some HUD display items. Indeed, I do not have an axis named “horizontal” anymore, but it looks like the Event system wants something by that name.

Do I need to have a “horizontal” axis for events to work? Should I find and modify the build event scripts to use my already-named axes? Since I’m not using the HUD for input, should I just nix the EventSystem altogether? What’s the right path here?

Check your EventSystem in your scene. if you see at the inspector you will see the Standalone Input Controller. change the Horizontal input to your Custom-named Input.