java.lang.IllegalArgumentException: Image width and height must be the same
	at com.jme3.util.SkyFactory.checkImage(SkyFactory.java:102)
	at com.jme3.util.SkyFactory.checkImagesForCubeMap(SkyFactory.java:122)
	at com.jme3.util.SkyFactory.createSky(SkyFactory.java:160)
	at com.jme3.util.SkyFactory.createSky(SkyFactory.java:143)
	at com.jme3.gde.terraineditor.sky.AddSkyboxAction.generateSkybox(AddSkyboxAction.java:67)
	at com.jme3.gde.terraineditor.sky.AddSkyboxAction.doCreateSpatial(AddSkyboxAction.java:53)
	at com.jme3.gde.core.sceneexplorer.nodes.actions.AbstractNewSpatialWizardAction$1$1.call(AbstractNewSpatialWizardAction.java:73)
	at com.jme3.gde.core.sceneexplorer.nodes.actions.AbstractNewSpatialWizardAction$1$1.call(AbstractNewSpatialWizardAction.java:70)
[catch] at com.jme3.app.AppTask.invoke(AppTask.java:142)
	at com.jme3.app.Application.runQueuedTasks(Application.java:585)
	at com.jme3.app.Application.update(Application.java:598)
	at com.jme3.gde.core.scene.SceneApplication.update(SceneApplication.java:267)
	at com.jme3.system.awt.AwtPanelsContext.updateInThread(AwtPanelsContext.java:157)
	at com.jme3.system.awt.AwtPanelsContext.access$100(AwtPanelsContext.java:13)
	at com.jme3.system.awt.AwtPanelsContext$AwtPanelsListener.update(AwtPanelsContext.java:37)
	at com.jme3.system.lwjgl.LwjglOffscreenBuffer.runLoop(LwjglOffscreenBuffer.java:120)
	at com.jme3.system.lwjgl.LwjglOffscreenBuffer.run(LwjglOffscreenBuffer.java:146)
	at java.lang.Thread.run(Thread.java:722)