Uncaught exception: Kotlin. When opening JavaFXGL application..

So when i ran the program/application yesterday it worked perfectly, however when i tried running it today(without making any changes) this error message came up:

Exception occurred: kotlin.KotlinNullPointerException : null
E: com.almasb.fxgl.input.Input$scanForUserActions$1.accept(Input.kt:481)
E: com.almasb.fxgl.input.Input$scanForUserActions$1.accept(Input.kt:28)
E: java.util.HashMap.forEach(HashMap.java:1289)
E: com.almasb.fxgl.input.Input.scanForUserActions(Input.kt:466)
E: com.almasb.fxgl.app.GameApplication.runPreInit(GameApplication.java:338)
E: com.almasb.fxgl.app.GameApplication.access$700(GameApplication.java:81)
E: com.almasb.fxgl.app.GameApplication$FXGLStartTask.succeeded(GameApplication.java:147)
E: javafx.concurrent.Task.setState(Task.java:724)
E: javafx.concurrent.Task$TaskCallable.lambda$call$499(Task.java:1434)
E: com.sun.javafx.application.PlatformImpl.lambda$null$172(PlatformImpl.java:295)
E: java.security.AccessController.doPrivileged(Native Method)
E: com.sun.javafx.application.PlatformImpl.lambda$runLater$173(PlatformImpl.java:294)
E: com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
E: com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
E: com.sun.glass.ui.gtk.GtkApplication.lambda$null$48(GtkApplication.java:139)
E: java.lang.Thread.run(Thread.java:748)

I don't know what else i can describe, other that im running java 1.8 and the newest version of fxgl. (I have tried removing the the kotlin plugin, however that didnt help.)(Other applications made in JavaFXGL still work as usual, its only this one.)

Do any of you know the problem might be?

- Mads Nielsen