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I have a problem with Assignment 4b as it is all working out in the design and I don't receive any error messages in the code itself, but I can not run it. the console gives me a java.lang.NullPointerException, and then a few lines where there apparently is supposed to be a problem, but I can not figure out what that problem is supposed to be

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  • This does not give us enough information to help you. You should at least show the code you have on the indicated lines. Eg. MachineUI.java line 220. So show the code of your setButtonLabel() method (with line numbers). – Fjodor van Slooten May 16 at 6:40    

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