Game crashes after removing the button that's binded to "Tabbing Modifier"

[SomethingSomethingV2]

Here's a link to a video that shows how the crash happens just in case my wording wasn't clear: https://drive.google.com/file/d/1ap5nYbMuf7ehEqr_nRKmfU-uITtknaEV/view?usp=sharing

This is the version I was playing on:

11:35:08.262 [main] WARN  o.t.e.rendering.nui.asset.UIFormat - Field 'columnRatios' not recognized for interface org.terasology.nui.UIWidget in {"type":"RowLayout","columnRatios":0.4,"horizontalSpacing":12,"contents":[{"type":"UILabel","text":"NEO"},{"type":"UIButton","text":"${engine:menu#input-settings-apply}","id":"neo"}]}
11:35:35.348 [main] ERROR o.t.engine.core.TerasologyEngine - Uncaught exception, attempting clean game shutdown
java.lang.NullPointerException: null
        at java.base/java.util.Objects.requireNonNull(Objects.java:233)
        at java.base/java.util.Optional.of(Optional.java:113)
        at java.base/java.util.stream.FindOps$FindSink$OfRef.get(FindOps.java:194)
        at java.base/java.util.stream.FindOps$FindSink$OfRef.get(FindOps.java:191)
        at java.base/java.util.stream.FindOps$FindOp.evaluateSequential(FindOps.java:150)
        at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
        at java.base/java.util.stream.ReferencePipeline.findFirst(ReferencePipeline.java:647)
        at org.terasology.engine.rendering.nui.layers.mainMenu.inputSettings.InputSettingsScreen.onClosed(InputSettingsScreen.java:306)
        at org.terasology.engine.rendering.nui.internal.NUIManagerInternal.onCloseScreen(NUIManagerInternal.java:283)
        at org.terasology.engine.rendering.nui.internal.NUIManagerInternal.closeScreen(NUIManagerInternal.java:278)
        at org.terasology.engine.rendering.nui.internal.NUIManagerInternal.popScreen(NUIManagerInternal.java:449)
        at org.terasology.engine.rendering.nui.animation.MenuAnimationSystemStub.triggerToPrev(MenuAnimationSystemStub.java:22)
        at org.terasology.engine.rendering.nui.animation.DeferredMenuAnimationSystem.triggerToPrev(DeferredMenuAnimationSystem.java:28)
        at org.terasology.engine.rendering.nui.CoreScreenLayer.triggerBackAnimation(CoreScreenLayer.java:365)
        at org.terasology.engine.rendering.nui.layers.mainMenu.inputSettings.InputSettingsScreen.lambda$initialise$4(InputSettingsScreen.java:174)
        at org.terasology.nui.ActivatableWidget.activateWidget(ActivatableWidget.java:46)
        at org.terasology.nui.widgets.UIButton.activateWidget(UIButton.java:203)
        at org.terasology.nui.widgets.UIButton$1.onMouseRelease(UIButton.java:94)
        at org.terasology.nui.canvas.CanvasImpl.processMouseRelease(CanvasImpl.java:266)
        at org.terasology.engine.rendering.nui.internal.NUIManagerInternal.mouseButtonEvent(NUIManagerInternal.java:678)
        at org.terasology.engine.rendering.nui.internal.NUIManagerInternalMethodAccess.invoke(Unknown Source)
        at org.terasology.engine.entitySystem.event.internal.EventSystemImpl$ByteCodeEventHandlerInfo.invoke(EventSystemImpl.java:399)
        at org.terasology.engine.entitySystem.event.internal.EventSystemImpl.sendConsumableEvent(EventSystemImpl.java:274)
        at org.terasology.engine.entitySystem.event.internal.EventSystemImpl.send(EventSystemImpl.java:253)
        at org.terasology.engine.core.bootstrap.eventSystem.AbstractEventSystemDecorator.send(AbstractEventSystemDecorator.java:67)
        at org.terasology.engine.network.NetworkEventSystemDecorator.send(NetworkEventSystemDecorator.java:54)
        at org.terasology.engine.core.bootstrap.eventSystem.AbstractEventSystemDecorator.send(AbstractEventSystemDecorator.java:67)
        at org.terasology.engine.recording.RecordingEventSystemDecorator.send(RecordingEventSystemDecorator.java:32)
        at org.terasology.engine.entitySystem.entity.internal.BaseEntityRef.send(BaseEntityRef.java:188)
        at org.terasology.engine.input.InputSystem.send(InputSystem.java:525)
        at org.terasology.engine.input.InputSystem.sendMouseEvent(InputSystem.java:497)
        at org.terasology.engine.input.InputSystem.processMouseButtonInput(InputSystem.java:217)
        at org.terasology.engine.input.InputSystem.processMouseInput(InputSystem.java:196)
        at org.terasology.engine.input.InputSystem.update(InputSystem.java:131)
        at org.terasology.engine.core.modes.StateMainMenu.handleInput(StateMainMenu.java:114)
        at org.terasology.engine.core.subsystem.lwjgl.LwjglInput.postUpdate(LwjglInput.java:39)
        at org.terasology.engine.core.TerasologyEngine.tick(TerasologyEngine.java:521)
        at org.terasology.engine.core.TerasologyEngine.mainLoop(TerasologyEngine.java:472)
        at org.terasology.engine.core.TerasologyEngine.runMain(TerasologyEngine.java:448)
        at org.terasology.engine.core.TerasologyEngine.run(TerasologyEngine.java:414)
        at org.terasology.engine.Terasology.call(Terasology.java:189)
        at org.terasology.engine.Terasology.call(Terasology.java:69)
        at picocli.CommandLine.executeUserObject(CommandLine.java:1933)
        at picocli.CommandLine.access$1200(CommandLine.java:145)
        at picocli.CommandLine$RunLast.executeUserObjectOfLastSubcommandWithSameParent(CommandLine.java:2332)
        at picocli.CommandLine$RunLast.handle(CommandLine.java:2326)
        at picocli.CommandLine$RunLast.handle(CommandLine.java:2291)
        at picocli.CommandLine$AbstractParseResultHandler.execute(CommandLine.java:2159)
        at picocli.CommandLine.execute(CommandLine.java:2058)
        at org.terasology.engine.Terasology.main(Terasology.java:138)
11:35:35.349 [main] INFO  o.t.engine.core.TerasologyEngine - Shutting down Terasology...

[soloturn]

added the exception.

[BenjaminAmos]

https://github.com/MovingBlocks/Terasology/blob/14937d24b851b300b3b8f569cfb86205a29626f2/engine/src/main/java/org/terasology/engine/rendering/nui/layers/mainMenu/inputSettings/InputSettingsScreen.java#L306-L308

I'm going to take a guess and say that bindsConf.getBinds(new SimpleUri("engine:tabbingModifier")) returns null?

NUI has some special behaviour for the tab key which allows for tabbing through UIs. Some things may have been slightly broken when we moved the NUI code into https://github.com/MovingBlocks/TeraNUI.