IntelliJ gui creator: JPanel gives runtime null pointer exception upon adding any component

For anybody who is using IntelliJ's GUI creator and receiving the same error, I fixed the problem by manually setting the panel's layout manager in the code instead of choosing different layout managers within the GUI creator.

Example:

questionPane.setLayout(new BoxLayout(questionPane, BoxLayout.PAGE_AXIS));

I've filed the issue as a bug on the JetBrains website and received the following answer:

For fix NPE, please add a child component to a JPanel with GridLayoutManager with GridConstraints like this:

panel.add(new JLabel(), new GridConstraints(...))

or use other layout.

Using the GridConstraints solved the problem for me just as using another LayoutManager.

I shortened & edited the answer for readability

I got the same error as you did. I have a JPanel with Layout Manager set to GridLayoutManager Intellij. When I tried to add any component to this panel, I was getting the exception.

I then went into the GUI editor and changed to BorderLayout and everything worked fine. I am not sure why it isn't working for you.