Had this when I dragged a missile computer to the support slot of a cannon computer. Both computers were assigned to my hotbar.
Can't reproduce though.
java.lang.ClassCastException: org.schema.game.client.view.gui.weapon.WeaponSlotOverlayElement cannot be cast to org.schema.schine.graphicsengine.forms.gui.newgui.ScrollableTableList$Row at org.schema.schine.graphicsengine.forms.gui.newgui.ScrollableTableList$Row.checkTarget(ScrollableTableList.java:786) at org.schema.schine.graphicsengine.forms.gui.newgui.ScrollableTableList$Row$1.callback(ScrollableTableList.java:697) at org.schema.schine.network.client.GUICallbackController.execute(GUICallbackController.java:64) at org.schema.schine.input.BasicInputController.updateInput(BasicInputController.java:234) at org.schema.game.client.controller.GameClientController.updateStateInput(GameClientController.java:1465) at org.schema.schine.graphicsengine.core.GLFrame.doFrameAndUpdate(GLFrame.java:673) at org.schema.schine.graphicsengine.core.GraphicsContext.mainLoop(GraphicsContext.java:828) at org.schema.schine.graphicsengine.core.GraphicsContext.startUp(GraphicsContext.java:725) at org.schema.game.client.controller.GameMainMenuController.startGraphics(GameMainMenuController.java:1150) at org.schema.game.common.Starter.startMainMenu(Starter.java:1459) at org.schema.game.common.Starter.main(Starter.java:1003)